It sounds like you have a toe picker. Its common in Bobs. Alot of times its from over crowding a bit, but I had one that did it at 2 days old. A change from brooder to grow out pen triggered it to start once too. Alex could very well be right, something grabbing birds from underneath, that happens too. Watch your birds, if one walks around with his head down, looking at the others feet and, them pecks. Thats your toe picker. Toe picker's feet will have no wounds... If you can catch him and get him out, the others will heal fast. Blue kote will cover the wounds and make them less of a target too. I made the mistake of trying to "reform" a toe picker once....no more. Once I find out for sure, the bird is on the menu. Only other option To stay in my pen would be a bit...Good luck, Bill