So, as some of you know, I made a 4ft square brooder out of Styrofoam and lined it up to about 6in with a black tarp. Well, the little buggers have been EATING it. There is a hole, 1.5in tall, 3-4in long all the way through the nearly inch thick foam. They eat their crumbles, but, how mad/worried should I be about the foam? I've put things all around the sides to keep them away from the walls, but they seem to find empty spots..