some people feed superworms but i personally don't recommend them. they can actually bite the gecko on the inside of the mouth (or elsewhere) when they are trying to eat them. my vet once told me a horror story about a chameleon that this happened too and it refused to eat for a very long time afterwards, firstly because it had a bad reaction to the bite causing its tongue to swelled and require treatment, secondly because it then seemed to be afraid of any food at all because it must have associated eating with pain.

i used to feed them before my vet told me this story and i could easily see that the leos would try not to let the mouth of the worm touch them if possible--one of them would even squint and flinch and try to grab the worm from a distance, as if he had been bit before and was attempting to avoid another.... so yeah, i just feed mealies and crickets right now.