A good diet for Crocodile Skinks Tribolonotus gracilis would consists of calcium/vatmin dusted mealworms. You may try other food but chance are theymay not take it. Mine have taken waxworms, but only a few months a year. Also it is best to put them in a container that they cannot escape. I put my container in the shoe box/hide spot in the cage. They seem to have a quicker feeding response this way. Now about lighting. It is best to have a special reptile light. They do need a little exposure to UVB lighting. They get ths exposure when they come out and lay in there water source.
A site that has a lot of information:
http://www.tribolonotus.bravepages.com
Also I'm in the work of a website too on Croc skinks, but i've been running behind schedule a lot lately, but i hope it will be done soon, so check that out in a week.
If you have any more question you can post another or email me at 594@jacksonexplorers.com
Crocodile Skinks Tribolonotus gracilis http://mikesreptiles.4t.com