So.........I was thinking poison dart frogs(:

[JimO]

The only thing that I would add to Berkmike's advice (very good and concise) is to emphasize that a thicker leaf litter (3+ inches deep) will facilitate sustaining healthy populations of springtails, isopods/woodlice, and other microfauna. Not only do they provide a variety of food, but springtails feed on fungi and isos/woodlice will act as an effective cleanup crew - even consuming the frog droppings.