My best friend has one and to be honest with you, I never see the darn thing eat! He just swims around the tank all day.... Maybe they eat through osmosis and just absorb all the nutrients in the water! Hahaha I need more sleep...
For the two years I have had them so far my pictus and white line pim have eaten mostly shrimp pellets. I also feed them earthworms, veggie and cichlid flakes and sinking catfish waffers. Yesterday I saw one eat a chunk of bananna that was ment for the goldfish.
lol, mine is so annoying! just swims up and down in the ONE corner of the tank....
the behaviour is disturbing and he does strike fo live fish, only very small barbs.
He eats blood worms.
They like to live in groups so I believe that behavior comes from the lack of other catfish. I only keep two, and they are not even the same species but tehy do not do that.