I usually feed my frogs nightcrawlers from walmart but they will also eat European nightcrawlers aka Super red worms which are also available at wm. The euros are smaller and might be easier to feed unless you cut the nightcrawlers up. Mine go crazy for worms and often get into a tug of war over them. I occasionally add ghost shrimp to the tank as well. The frogs eventually pick them off but they do some cleaning too.