Just an FYI-...I raise flightless fruit flies for my daughter's dart frog. We currently have more than can be eaten by that little guy. I decided to dump some in with my rice fish to see what would happen. The flies are small enough they can kind of walk around on the surface tension of the water. They didn't last long though. Once the fish noticed what was going on they went bonkers gulping them down. Tried some in the guppy tank, same thing, feeding frenzy. I'm not sure if this is a common live food, but they're easy to culture and inexpensive if you're raising them yourself...