I love the African Dwarf Frogs! They're just so funny to watch. Funny story about the Neon Tetras though. We had a crapload of Neon Tetras and Red Rasboras a long time ago...back when the pleco was still an acceptable size. Well, it wasn't long before they started to completely disappear, one at a time.
After a complete overhaul of the tank and filtration, there was NOTHING to be found. Turns out what had happened was that the pleco's mouth had gotten so big (even then) that he actually sucked several of them up accidentally.
Needless to say, anything too small is definitely out of the question now! LOL