We did treat it, and put him in an individual container. His hand looks really bad. Curled up and he doesnt open it. I cant really tell if the swelling has gone down at all. I dont know if the lid could have done this to him, but they will push up and try to escape. We were thinking maybe he got bit by a cricket and got infected? I dont know if that sounds ridiculous or not. I know crickets can be nasty.