Every Correct Thing You'll Need To Know About Mason Bees and Bee Condos For The Beginner 

Very good.

@@hutchingsbeeservice I don't know where in the world either of you are but THANK YOU (from me in the UK) :)

hutchingsbeeservice hello please let me know if you sell your mason bee homes?

Thanks. It's been 30 years this year since I've been experimenting with Osmia lignaria as a fun side project as an entomologist and I just thought I'd put my experiences out there which you can take or leave it. When ever I give presentations or put on information booths at say, agriculture or fall fairs etc., I get asked a lot of questions about "mason bees" so of course, I have to address this particular group of bees a lot. However, my research is assessing the fauna of native bees in my province of B.C. especially in the Kootenays where I live. Cheers.

My Dad and I did lots of experimenting starting in 1989 so we learned what did and didn't work for us. However, I wouldn't discount you trying your own ideas as depending on where you are, you may discover different compliment of bees. Some of the obvious harmful concepts in cavity nesting boxes for native bees, I wanted to prevent folks from continuing down that road as the internet is full of this, hence this video.

No probs. I wish I could do more but between these videos and my website, I feel it's covered from my angle of experience. Cheers, Gord.

Thanks Christopher, and good to know the count as I never really look at that stat. I don't know what else to post in the way of bee videos except for maybe some videos of actual native bees pollinating but I've kind of covered mostly what I wanted to put out about the common mason bee that is so popular. My website is here btw: sites.google.com/site/hutchingsbeeservice/home Cheers.

That's what you get for free editing software on the internet eh?

hutchingsbeeservice lol for sure! Great info still! I’m learning and getting interested in mason bees.

I wish you were closer to where I live as I have literally tens of thousands of cocoons that I have to give away, plus dozens and dozens of condos and barns that I'm burning. Where I'm moving to, I can't export this subspecies of mason bee, plus I have way too many barns after having them up at farms and orchards in this area. No one is carrying on what I've been doing here for decades and now I'm retiring finally and moving 1000 miles away.

hutchingsbeeservice I’ll take any help you can offer! I noticed from your site you don’t believe it’s a good idea to ship very far. If there is any equipment or just help in general I’m listening.

No it's not a good idea when it comes to shipping willy nilly. Just look at how many things human's "management" of nature has turned into catastrophe. Localised diseases, pathogens, parasites and parasitoids should not be spread along with cocoon shipping, let alone genetic strain that goes along with it. It should be inherit in one's common sense.

My dad and I started with a variety of sizes to find which species liked which size , shape and length etc. which I'm just saying you could try as well. If you want to see what a contact of mine is doing in Oregon, you can see that he did much the same thing. www.opb.org/news/video/dro-2-orf-3003-03-mason-bees/?t=860720

Sorry but I don't know where to buy one as I had one made by a machinist where I used to work (now I'm retired), and the other my Dad took a regular high speed steel dado "wobble" blade and had it machined to a curved tooth instead of the square ended one. I've also run my regular saw blade most of the way down which leaves a groove the width of the saw itself. Then I measure a drill bit the desired length, say 8-11" and drilled to that point without going through the other end (back). I did this with two clamped boards or trays, then pulled them apart making a perfect circle to insert a paper tube if that's what you want. I just used the wood itself. As for cleaning, I just wire brush, then sand a bit and leave it for next year. If they have mould then you can clean with your method but I just burnt it a bit with a propane torch, then sand. Hope that helps.

If you go to my site about past research (http:sites.google.com/site/hutchingsbeeservice/my-research-both-current-and-past-projects), you'll see what I discovered for optimal length for male to female offspring ratios for progeny. Roof is something you can experiment with so have at it. Ants, yes, they are a nuisance which is why I would have on a pole with tanglefoot goo around the post to keep ants and earwigs from climbing up. They will find clay of the correct consistency without us knowing how they do it. I found females going in between the rocks of a rock wall to get what they wanted. Don't fret about that. Lifespan depends on the weather and how active they are every day. On average, (and you can do a publication review on this one in academic sources), they lay about 20-30 eggs. I found that on a decent day, they can lay about 1-1.5 eggs per day (including provisioning and mud divider walls), which means they last just over 30 days. That's for my area anyways but might be different where you are. When they steal each other's channel or start a new one in an already established channel, they may leave a space to start over again which can upset your viewing research of which belongs to which female but the space tells you that this is a new female. Also, a female senses when she will exhaust her egg laying abilities and start a new adjacent channel and won't go all the way down and instead starting only part way down a channel to lay her remaining brood before expiring. Personallly on the ratio for a provided "nest", I would have fewer males per females as one male can service many females and they continue to try mating only to be continually repelled by already mated females. Most garden store, internet bee experts etc. really don't have a clue. Only the mellitologists out there know and they would refer you to past and current research papers, something I did when I was at university working on my projects. Look up some stuff by the following authors: Tepedino, Torchio, Rust etc. and look at their bibliographies to find even more folks research papers. There's a wealth of information in there and you'll laugh at all the pathetic videos on YT going on about what is "correct", hence my putting my goof ball videos up to try and answer them. Good luck! Cheers, Gord

Thank you very much for that extremely informative reply. After posting my questions I did discover your main website and pretty much exhausted the information there. As it turns out I live very close to you in Victoria, just a few blocks from Oak Bay. I'll be watching over the winter to see if you put any information seminars in the area.

Sorry but I have moved to the west Kootenays after being in Cobble Hill for 7 years but yes, I was originally from OB. I'm always up for presenting in Victoria and will still fit things in should I ever be asked to. Cheers.

@@hutchingsbeeservice I couldn't get your site to work..

They do not necessarily return to the same hole but bees are attracted to their own "smell", hence used condos working better. Definitely try different diametres of holes as you should get (depending on your area for habitat), Hylaeus, Heriades, small spp. of Mecachile, Anthidium and Osmia, besides a plethora of cool cavity nesting wasps so try 1/8" - 5/16" channels. I'm always keen to see folk's results and applications of where they have their setups around the world so please send me photos if you're interested. Good luck. Gord

Topanga looks quite interesting from my perspective here in the Kootenays. The higher elevation looks drier and this would be conducive for many different types of native bees. However, I don’t know how many would readily take to a condo but I would definitely make a variety of condos and put them in all sorts of areas, especially in the wild. If you do, take way points of where you “hide” them so you don’t forget where to find them again. These videos are mainly aimed at folks who want to try and have a captive population of the native and popular pollinating bees such as Osmia and Megachile spp. However, as an entomologist, I am very keen in all native bees and do these cavity nesting videos for the gardener type enthusiast. My website elaborates further on my native bee research. For the depth of a square dado, go 5/16” deep but round, maybe a bit more like 3/8”. By all means experiment with depth and width. I also use ¼” and my three round toothed blade is a homemade thing so I have no brand name for it. Topanga looks like an area that would be at risk from fire if that were ever to happen? I still have 12” of snow on my garden and orchard but saw my first bumble bee queen emerging yesterday. There’s no flowers up yet here whatsoever. Good luck.

That is a hard question to absolutely answer but why not go to four different stations as most native bees go about 100 yards-ish apparently but I've never actually done any work in this area myself but read various papers over the decades guessing at this. You can always start with less and go to more in subsequent years as per required especially if you're going to purchase local cocoons. If they stick around and you have a suitable location for nesting as well as food, then you should get a good return, do a cleaning program and have way more for the next year, etc. If they come out early and search for food and your intended crop to be pollinated is not ready, they may fly off and not return so I recommend having another food source nearby. Dandelions work great for this and once your crop is in bloom, mow the dandelions down. Be observant of your flowers and who's visiting/pollinating them, you'll probably get bumble bees and Colletes spp. and Andrena spp. of bees. It sounds great so hopefully you'll report back. I wish I could see some photos of things in action next year.

@@hutchingsbeeservice Thanks for the feedback. Your thought regarding having an alternative food source available for early feeding sounds good. I'm not sure if I'll be purchasing cocoons. I may just install a couple of houses and see what shows up. I'll let you know how things turn out. Is there an email address I could send some photos to?

@@howiehall9500 It is found on my website which is connected to my videos but here it is the website sites.google.com/site/hutchingsbeeservice/home but here is my email: odonatas@uvic.ca Cheers.

After the bees have finished laying, and this is very important, and the larvae have pupated into their cocoons, hopefully with a partial or better yet, a metamorphosis into adulthood, is when to do your extracting and cleaning. Also, it has to be a cold environment so as to not initiate the bees into thinking it's "spring". For my area this is usually around the end of October to mid-December.

Please check it out here in this video going over that: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VMmJ0G80bOU.html Thanks.

It's about extracting live bees inside their cocoons without killing them. You have a tad amount of research to do so you're welcome to dig a little deeper.

You go as minimum as you want but you'll only get males. "End of the season"? The adults emerge in spring which varies due to particular weather patterns, and goes until the same. So it can be anywhere from late Feb. to maybe mid-June but really, for my area anyways, it's height is around April and May. The developing young within the channels continue to live for another year before emergence the following spring and repeating the cycle.

@@hutchingsbeeservice Thanks for the reply. What is the minimum depth you recommend to get a good yield of females? Six inches? Eight inches? And what time of year do you go in and recover the cocoons?

@@seansherlock9047 I did a project many years ago which can be seen here: sites.google.com/site/hutchingsbeeservice/my-research-both-current-and-past-projects Essentially, the most efficient length for female progeny was a whopping 11" but it's ungainly to deal with so I mostly use trays about 8" long. I extract the cocoons around Nov.-Jan. in a cold environment which you can view at my other videos.

Maybe one day. I do have photos on my website for what it's worth.

In my opinion, you should never purchase bees unless it's a commercial operation for the introduced and non-native honey bee. This especially goes for our native species. Let's not mis-manage yet another organism in our habitat, especially introducing species not normally found in the very place you're letting them go. Even in the greenhouse industry, there is a fair amount of escapees from bumble bees that they utilise within the supposedly isolated green houses but it has been shown that there is spill over of diseases/pathogens to the wild bees found in the vicinity of green houses. We have something similar here in B.C. with salmon whereby Atlantic salmon kept in "closed" net pens have passed on their associated diseases and parasites to the wild stock going by. Go to my webpage to read what I state about shipping bees: sites.google.com/site/hutchingsbeeservice/getting-started

thank you for your video, I will not be buying any mason bees, I have tons of carpenter bees, they are every where, I got some in the deck as I walk out the back door. I also say hi guard bee ooo1a the access code is 0001b and they always let me pass

After nesting and when the last larva has spun their cocoons so a safe bet is November and December.

So what your telling me, is that you remove the cocoons in November or December and store them where/how, until spring? Is there a problem if you just leave the cocoons where they are until spring? I guess you have to get the crayons out for me. Sorry, LOL

Remove them as per my cleaning videos, and put the cocoons in an emergence container like a cardboard or wooden box outside away from moisture and predators. Outside meaning a non-heated room like a garage, or outbuilding and then make sure to put the emergence box outside outside, when the bees start to emerge naturally depending on where you live. Some folks at this time put them in the fridge to stall them a bit for a captive pollinating service such as an orchard or such. If you leave them until spring, you risk triggering them into emerging while you're in the act of cleaning (not good). They need to come out on their own time.

Got it, the nest box is built, thanks a lot.

Imagine you come out from a large mall faced with the horror of not remembering where you parked your car. Then multiply this with which floor of the parking lot complex you were on. For humans, we use letters and/or numbers to designate this where as hymenoptera (bees, ants & wasps) utilise patterns. This is why bees waver backwards in ever increasing flight paths when they first leave their nest to orient themselves with their surroundings of where their nest is situated, just ask honey bee keepers about this with their new foragers leaving the hive. Native bees and wasps do the same thing. In their limited neuron capacity, bees and wasps absolutely excel at pattern recognition however, hence their superiority at pollinating the same species of flowers over and over with very little switching to different species as they forage about. This also works well for the plant that wants to be pollinated by their own species. This is one of my most popular presentations I give to the public which is called: "The Coevolution of Native Bees and Flowering Plants". So the best thing we can do to make their homing in on their particular nest cavity is to leave markers easily laid out for them, hence the colour markings. Why red? Well, red to bees is black/dark so it stands out more as a contrast, which is why bees don't do red flowers very well but hummingbirds do as birds have different uv detectors or lack thereof in their eyes. Sure, I've been having fun with trap nesting cavity nesting hymes but I've been an entomologist all my life. Mason bees are just a bit of fun. No to the designated FB thing for me. I just have FB for real family and friends. This is a volunteer hobby for me only and I'm keeping it that way. That's why I get annoyed at pros that contact me, then use my information to further their entrepreneurism claiming it as their own. Sorry for the rant. I hope your purchased megachiles and osmias are local subspecies? You'll see my advice on my website about this which is another entrepreneural endeavour that is ill advised in the natural world. I'm first and foremost an entomologist and not an entrepreneur. Thanks for your questions.

You might find something here if you wade though. sites.google.com/site/hutchingsbeeservice/home

I'm definitely okay with paper tubes but yes, the gaps between can be problematic and bees will go in between and develop nests cells. Also, and to a minor extent, it's just an added expense that I choose to not bother with. As for size, sure 5/16 is common for most Osmia species but why not vary your diametres and see what else (other bees and wasps) you get. I'm not sure when for your area but I would suspect considerably earlier than where I am so put them out early and see what happens. Watch out for moisture. Paper's bad for this. That's what I've done in the past. Cheers, Gord

@@hutchingsbeeservice thank you so much for your answer. I'm going to give it a try :)

Treated wood is not good as the nectar and pollen provided within the channels, especially on a hot day, will transfer undesirable chemicals into the food source. Paint on the outside is fine but not in the interior channels(grooves) themselves. Thanks for the good question and I hope others will take note.

@@hutchingsbeeservice Thank you for the reply, that has given me some peace of mind.

Well the whole idea why I utilise a clear cover on top of a wooden channel is for observing what's going on inside and to learn a more intimate biology of cavity nesting insects, in this case, bees. This is highly conducive for the education that adults glean from this perspective, let alone a child so it would be a real loss of opportunity for a child not to witness this and learn from it also. When you have bamboo, will you simply leave the bees to their own devices a.k.a., their associated diseases, parasites and parasitoids? At least with raspberry canes, if you're careful, you can cut/split them open at the commencement of the year and go on to a cleaning program which can be seen in my other video on using sand and tubes etc. What a shame not to have access to this. I do build and mail these out to people but the postage cost is ridiculous, hence my basically no longer doing this readily since the rates went up so drastically starting about 12 years ago. I did just send one off to Pennsylvania and it cost the woman $32CAN for me to send to her. She was insistent in getting my product and simply could not build it herself. I'm not here to sell stuff but merely educate and try and get people to build their own and copy my design. My website goes into more details perhaps if you want to check that out. I hope this helps.

I suppose my thought was that when I took out the parchment/regular paper inserts, at that time we could unravel it and inspect what had happened throughout the season....then clean and reinsert paper tubes for next season. Not sure if that makes sense, this is all new to me. Where are you located though? I am in Nanaimo, BC and it seems you may be close?

Looks like you are in Victoria? Wow, that would be great if so. Do you ever get up to Nanaimo? Maybe we can meet here or there and I could get a couple condos from you! Great Christmas or birthday gifts.

Sorry but I'm in Cobble Hill but leave in three days to retire in the Kootenays.

Yes, the option of parchment paper will work just fine and like you said, you won't be able to view within but that's up to you. You may eventually get yourself a condo like mine or I can make you one in the future as I've packed away all my stuff ready for the move. I simply can't get one for you before I head out.

Ants, spiders and earwigs are very much a deterrent for mason bees but ants are the worst and once a bee starts, the ants will put them off and rob all the provisioning within the channels. If the condo was on a stand-alone stake, I put tanglefoot resin part way up to hinder anything crawling up. If it's suspended from a tree, not only does it swing in the air which bees don't like, ants will crawl down and move in.

@@gordhutchings3699 Thank you. I shall research tanglefoot resin and/or it's equivalent in the UK. It's 3 foot up on a mighty ash tree (Fraxinus excelsior) nailed tight so I doubt it swings at all? I shall review what your video says. Many thanks for replying so long after the orig upload. In the UK, the ants would have travelled up I believe but maybe I have a lot more learning to do.

I rewatched and now know I'm the bod who wants to see the bees coming and going. Here's what I've got www.amazon.co.uk/gp/product/B001HIYW44/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I am in a rural area, organic, trees and fields and prob plenty opportunities for bees. I don't want to kill them, should I remove my 'condo' in your opinion (much appreciated)? Design taken from yours I hope.

Why remove it? Keep going. I just recommend doing a bit of cleaning program but I don't know what parasites you have there. Where are you exactly? It would be fun if you had a tray with a clear cover. Give me your exact measurements and I'll make you a tray with a clear cover if you think it'll work in your existing stacked condo design. I don't know what holds it together. You pay for shipping. You must be getting red mason bees where you are.

My website might help also so there should be a link? Otherwise search "Hutchings bees" or something like that. I'm just outside Meadow Creek, BC, Canada btw. My Dad died years ago so it's just me now. You said "you guys". Cheers. Gord

It is on my website "Hutchings Bee Serices" but it's 5/16" or about 8mm for the local Osmia lignaria that I was demonstrating in this particular video.

5/16" for most Osmia lignaria but other species which are smaller utilise smaller diametre.

This happens with a lot of folks. Get a dark container that is sealable and don't put it in direct sun so it gets overheated, and have a small hole about 1/2" near the bottom. Over time as the bees emerge on their own timeclock, they will seek out the only source of light which is their escape route, and away they fly. Leave it this way for the entire emergence season which depends on your location, and once done, your condo should be empty of everything viable. Anything left behind will be dead. Choose to do with your condo as you wish and I would suggest you use a type that can either be taken apart, or have extractable tubes. There's lots on the web but my design is relatively easy to make and maintain year after year so I would suggest something like that - your choice. Cheers, Gord.

Also, try here at my website for further info maybe: sites.google.com/site/hutchingsbeeservice/mason-bee-condos-for-sale

I have a 5/16 and 1/4" special round toothed blade I had a friend make out of high speed steel. He couldn't do in carbide so I only use on softwoods. 5/16" is the common size to use and I go anywhere from 8-11" deep. It's quicker than a router which I don't own or use anyways.

@@hutchingsbeeservice I agree that it would be way more efficient than a router. I would order a blade today that would make those channels on my table saw. I have three routers, but the table saw blade would be the best.

@@hutchingsbeeservice Where to you get the plastic covers that you use?

@@ordinaryguy6869 I usually have to go back to where I lived and get it by the 4x8 sheet. I have a small sample chunk left but can't remember what thickness it is. It comes with peel off on each side. I use it over and over for many years and soak and wash it carefully so as not to scratch. If you want, I can get a micrometre on it and let you know. I got it from a particular plastic supply business and I can ask them exactly what it is called and let you know. Otherwise I source other lighter/thinner, not as good of stuff like the replacement covers for protective shields say, for grinding. Plexiglass is too think and you have to use screws. Taping is way quicker and tape is cheap.

@@ordinaryguy6869 Like I said, it's a "home made" one but I had a tool and die buddy at work make it for me years ago. I'm now retired so can't get it done anymore. I've moved far from where I use to live. The video should show it up close of what it looks like. Some other guy who contacted me I think in England, he had one made for himself.

This is a good question and I have been asked very many times over the years when I give presentations and classes and yes, cedar works fine. I've been using it for many years with no deterrent for the bees. As far as their associated parasites being put off, I don't see any difference. Think about how many cedar shake sidings and roofs you've seen and if you look carefully, you'll sometimes see a plethora of mason bees going about their business in the gaps. However, the associated parasites and parasitoids associated along with them is horrendous, hence a good cleaning management system if you want to replicate this same thing in your captive pollination service in your condos and bee barns for your crops or whatever. So yes, cedar is fine. On others saying it's bad, I beg to differ but like everything else my father and I tried starting in the 80's, we gave it a go and figured out which was the best way to carry on and make yearly improvements. I would tell you to do the same. Good luck.

Pressure treated, no, as the wet pollen and nectar that the female lays down will possibly leach the chromated copper arsenate into the food. Cedar, yes. It's the best stuff to use but it's also more expensive. I find it far less apt to warp or split than the other woods. Fir is especially prone to do this when exposed to the elements. Plywood also has glues but more importantly for me, it dulls my high speed steel tools since I don't have carbide in my home made blade.

Cedar isn't expensive when you have a 50ft dead cedar and a friend with a lumber mill.

Not anymore as the shipping cost is so outrageous that it's just not worth it, hence these videos on how to make your own. However, if folks are insistent, then yes, I have continued to sell to those willing to pay for that. Just yesterday, I sent 4 trays off to someone in Arizona and the shipping to the US was $18 CAN, and she will make her own box to put the trays within . If someone lived near me here in the Kootenays, no problem, but I'm in a rather remote area to say the least.

The males only feed for their own sustenance and do not provisioning whatsoever for any offspring. Their purpose is to disperse and mate, but yes, in the act of flower visitations, they do perform a role in pollination service.

No and definitely not providing for the offspring in any way. They mainly consume nectar for quick carbohydrate energy for mating etc.

I have not witnessed this myself to too much except to say should you have a warm area directly above the pool where they congregate and warm up etc., perhaps they fall in? Without actually seeing this site myself I am left with only speculating. However, these bees (unlike the introduced honey bee), do not go to a water source for liquid. The native mason bees only obtain clay for their nest construction and once again, only the females do this. It would be interesting to see what sex ratio you have in your pool "rescues" as this can also be a result of mating as when the males pounce on the females, they can sometimes crash with gravity down to the ground. Should there be water there, they can succumb in the water. This is why I tell people not to have water below their bee condos as I've seen this happen many times.

I found them still on the ground, 13 males(white faces) 4 females

Sorry but I can't deduce a proper response without a complete picture of the situation. A 360 degree photo, plus time of day and temperature would help but I can't do anything more at this point. These bees don't simply die without some sort of cause, especially in a concentrated effort in a particular site. I've seen this but have figured it out pretty soon and rectified the situation.

would you know how I would upload a image into the message? I tried before and it did not work

let me try this prntscr.com/ixgl0f

Really, the only bee that sort of "destroys" human dwellings would be Xylocopa spp. (carpenter bee) as they can and do chew wooden structures. Other bees such as the megachilids like in your Osmia question, have large jaws used for manipulating the added nesting material such as petals, leaves, mud or gravel etc., but do not chew the cavity where they take up residence. They absolutely would go into previously provided openings within brick and mortar work but would not enlarge it. Some bees such as Anthophora will use water to regurgitate onto very hard-packed soils in order to soften them up so they can keep digging their burrows underground. All of these bees that chew soil or wood have a limited amount of activity on what their jaws can withstand which is why when it comes to identifying certain species of bees using keys that feature their jaw structures, one has to be aware of the highly worn teeth on them making that feature as useless for an identifying character. In my opinion your bees "chewing" mortar is simply not true. Taking up residence, yes but they do not damage it any further. Water inside cracks and even small seedlings can expand cracks and make structures break, especially water when it freezes and expands to ice. These are powerful forces in nature. I hope this helps.

@@gordhutchings3699 It helps very much. Thank you for your detailed confirmation. I had the impression that they would find holes in walls (I've often seen round holes in brickwalls). Those holes are very likely drilled by a human's drilling machine - perhaps for a purpose that might have been forgotten. When someone sees a solitary bee in that hole, they're quick to put the blame on the bee. ;) I also had the impression that the bee's jaws are not very strong, again a clear confirmation. I hope your thorough answer will benefit many people; I did learn a lot from it and I am very grateful that you took the time to reply. :)

You don't want to introduce a new species to an environment.look up rabbits in Australia. it would be better to find out what your bee is in your area.

How so? Care to share? I don't have any but I assume since he's been researching them and doing this for a decade that he's quite knowledgeable...

@@ah5721 Blocks of wood are perfectly fine if you don't use them for more than a year or two. Males and females pollinate, not just females. Oh, and THREE.... deep holes are not ideal. 6" is the best depth. Any deeper and it makes it too difficult for the deeper females to get out by the time the males are all gone.

@@stevenfeil7079 the point of deep holes is to increase the female to male ratio, as a single male can mate with many females. its more beneficial to have a higher ratio of females to males. Also a block of wood may or may not be fine, but a box that can be taken apart guarantees that it will be fine. pests like mites or carpet beetle larva can appear quickly and inside a block of wood you'd have no idea that all those bee larva are being devoured.

@@stevenfeil7079 This is absolutely why I pursued this hypothesis in my research at university based upon others such as Krombein, Rust, Tepedino and Torchio etc., and I found that the most efficient length for production of bees was 29 cm. Then I did this again for female progeny and the same result came about. A block of wood becomes a death trap after one year and is a breeding ground for disease and pathogens. 6" is definitely not the "best" depth unless you want a higher yield of males. A longer length does NOT make it too difficult for females to get out because I do an active extraction and cleaning program as per my other videos . All this research results can be found on my website. Yes males pollinate but not as much as the female. They only feed for their own sustenance and live substantially less. Females live longer and provide for their young, visiting many flowers many, many times a day.

@@ah5721 This person did not read my written introduction which goes with the video, nor did they go to my website showing the several photos of full 11" trays filled with bees. They also did not see my other videos whereby I extract all the cocoons (and everything else), and do a cleaning of the living cocoons, clean them using sand, and put in emergence boxes for next year. Do not worry, 11" was a scientific endeavour but I normally go around 8-10" for most folks for ease of installing a condo. 6" is most definitely a way to get a higher yield of males who yes, do some pollination, but nothing compared to the females. Nor do they live as long. They only feed themselves and have no effort in provisioning for the offspring. 6" is too short for my wants and the first 2-3" would be filled with males anyways. I hope this helps clear up any misinformation which is absolutely why I put this video out and labeled it as such. There's just so much garbage out there. Besides, I'm an entomologist who just happened to have spent some time with mason bees for fun. It was my father who got me interested in it with him.Cheers, Gord.