I took a half gallon milk jug and cut a hole on two sides with a hole in the top for pouring food into and attached it to the corner of their brooder. This completely stopped the problem. It costs absolutely nothing to try it!
Edit to further explain: I put the holes about 4 or 5 inches up and only big enough for them to poke their heads into (about the size of a golf ball). This way they can eat but not scratch. I then cut off a triangle at the top opposite the handle so that I could pour food in with a yogurt cup. My chicks live in a Guinea pig cage so I just zip tied the handle to the bars in the corner. Do not use string or twist ties (I learned that after they almost ate one). It worked so well I made a second one for their water. Now I don't have to pick litter out multiple times a day