Hmmm?..Strange.. Are they eating the shavings and are you wetting the feed?..Sometimes wet feed builds up in the corners of the beak. I never wet feed. Do they get plenty of water?..I also put a rock in the Brooder and Brood on sand with Chicks without Mommas. The rock is for them to hone or...
Sounds too warm to me too..Chicks also put off heat. Are you taking the temp at Chick height?..Do you provide a cooler area in the Brooder so they can get out of the heat?.
What type of Brooder?