Small Predatory Fish. I have a bog pond in the front yard that tends to invite mosquitoes, so every day i net out a bunch of mosquito larvae and feed to the killis. Afer knife fish are very predatory.

Adult pike, for example, will certainly eat lots of minnows and small sunfish, but they will also take large insects such as water beetles, shrimps, crabs, and crayfish, or even the occasional aquatic bird or mammal. Many species of fish, however, show morphological adaptations that facilitate their mode of feeding. Snakeheads (not in the us) and ambush species of puffers (arrowheads, congos, etc) will work well.