Hey, (if we talking about aquatic caecilians)
The worms I use for mine are Earthworms (Nightcrawlers), I usually find these in a fish bait store then place them in my worm gutloader and use them as I need them. I believe Ed mentioned that the Red Worms shouldnt be used because they produce something or other that tastes bad and can turn caecilians off worms.

I have fed;
Feeder Guppies (I breed em, and are much leaner then goldfish)
Ghost shrimp (when im feeling evil)
Strips of Beef Heart
Shrimp
But Nightcrawlers are my staple

The problems ive had with bloodworms is if not all of it gets eaten your water quality will suffer. The only time I use bloodworms is when Ive got babies and even then I prefer to use live Cali Blackworms. Hope this helps a bit.