Hi. I have 6 chicks ranging in age from 2.5 - 4 weeks. The last couple of nights they’ve all gone to sleep on their roosting bar instead of under the warmer. This seems super early to me, but it’s been a couple of years since I’ve had chicks. The oldest ones have lots of feathers but my youngest one is still mostly fluff and she’s up there with them! Will they just move themselves back under the warmer if they get chilly?