I have 6 chicks that are 5 weeks old. Most of them are fully feathered except of the back of their necks and maybe a little between their wings. I'm wondering how I should have my heat plate set up for them at this point. They are too big to all fit under it, and I've often caught them all sleeping in a pile at the opposite side of the brooder. Should I remove the heat plate at this point? Tilt it up so it's at a 90 degree angle? Or leave it so they can go under it if they want?