@@RobinDebrassio-vx6fl The expert opinion/advice used to be that babies could sleep on their tummy. Turns out that was contributing to cases of SIDS . So, now you only put the baby on their back, except for tummy time, which is a supervised time to help them strengthen all the muscles they need for that orientation of the body. They need it so they can move up to rolling and crawling and eventually walking, but when they are very little you have to keep an eye on them. And it can be uncomfortable if they aren’t strong enough yet.