They will eat insects, pellets, fish and crustaceans(freshwater clams, crayfish) It is normal for the catfish to lay around, they are night time predators. Yours can be trained to eat and be active during the day by feeding during the day.
Your catfish is still healing. My brown bullhead eventually became active when I was not around. The minute I would come into the room, it would immediately head for it's spot and stay there.
It took about 2 weeks before it would eat in front of me. Now, the bullhead cruises all the time.
It took about 27 days before it would eat. I got mine on 5-28-10. This catfish is truly my favorite in the tank.
Trust me, you will enjoy your catfish, the speed, agility and prowling behavior is worth it!!
My cat is 1 foot including the tail.