They are not picky eaters and there are lots of foods you can culture to feed them. Flightless/Wingless Fruit Flies, Bean and Flour Beetles, Springtails, and Isopods are some of the readily available feeders, some also double as tank janitors.
I do not feed crickets, not even pinheads. Crickets are evil things that will chew your animals if left in the tank with nothing to eat. Think of feeding pinheads and then a few months later seeing a monster adult cricket in there.
Bumble bee toads do well in groups, but are not as flashy or active as dart. Still a very cute toad.