Tetra's With Tetra's

Tetras of a similar size will often school together. If there is a large size difference, or a large difference in behavior (ie, rapid, constant swimming versus hanging in one spot for a while), they won't school together. However, in smaller tanks, schooling activity is seldom seen, due to the space restrictions. Also, fish only school when they feel threatened, so fish that school tightly when first introduced will often relax and not school once they are used to the tank. I'd probably just add a few more neons to your existing group.

The cat will eat anything it can fit in it's mouth. A small frog may be eaten, a larger frog may be safe. Hard to determine exactly.