It's very likely sick, yes. It might be very stressed or it's really sick. You should really see a vet. When an animal starts chewing on himself, that's not a good sign...
"There are other things in its cage to chew on."
He doesn't chew on himself for fun...
(does he bleed/chew really hard?)
"There are other things in its cage to chew on."
He doesn't chew on himself for fun...
(does he bleed/chew really hard?)