For those wondering where all those chicks came from, if you look on the tree beside Bunty and Babs, you can see a heart that says within it Bunty + Fowler. This would subtly imply that Fowler is the father to those chicks and we know how good Bunty is at laying eggs throughout the film.
*Nick:* The egg, obviously, rollin' along, happy as Larry, then crack! hatches into the first chicken. *Fetcher:* Yeah. But where'd the egg come from, then? *Nick:* What d'you mean "where'd it come from"? *Fetcher:* Egg comes rollin' along, 'appy as Larry, it's wonderin', where'd it come from? Without a chicken, you got no egg to come rollin' along. *Nick:* Well, conversely, without an egg to hatch into the chicken, there'd be no chicken to lay the other egg that hatched into the chicken that laid the egg I mentioned in the first place. *Fetcher:* So we got _two_ eggs now? *Nick:* No, we're still talkin' about the very first egg. *Fetcher:* Yeah, but what 'appened to the very first chicken? *Nick:* 'E's in the very first egg! Aren't you listening? *Rocky:* Uh, guys, guys, we're trying to enjoy paradise over here. *Nick:* Oh, sorry, guv. *Fetcher:* Beg your pardon. *Nick:* Won't happen again. *Rocky:* Thanks. *Nick:* Gitface. *Fetcher:* Pillock. *Nick:* Thinks 'e's such a bigshot 'cause 'e's got 'is name on a poster. These showbiz folk are all the same. *Fetcher:* Yeah, the rats are the stars, actually. But he does get all the birds. *Nick:* Yeah, of course they are. We do all the 'ard work, 'e gets all the credit. *Fetcher:* He gets everything, doesn't he? *Nick:* Yes, he does. Everything. *Fetcher:* You said it, mate. *Nick:* I know.