The habitat is probably not large enough for even one leopard frog. An adult needs an enclosure that's large enough for the frog to leap around without hitting against the walls. They are not upset by living alone; in fact, it's actually better for the frog to be housed alone, so you can tell which frogs are feeding regularly and also to guard against the spread of disease from frog to frog. I'd say an adult leopard frog needs the equivelant of at least a 20 gallon long aquarium when fully grown, a 10g is OK for starting out though. They do well on a diet of mainly crickets, using vitamin powder regularly, with some nightcrawler/earthworms every so often. tadpoles will eat boiled lettuce and crumbled fish food flakes.