Worth keeping a close eye on. When did that form? Was he rubbing his nose up against something? Loose bugs in the tank? You might want to put some unpasteurized/raw honey on it to help it heal but keep an eye out for it looking worse or spreading.
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!