Why Mosquitoes Don't Live in Ponds
Mosquito breeding habitat is a fairly well known. In the summer we hear news reports about dumping standing water our of old tires or empty flower pots. Ever wonder why they lay their eggs there and not in larger bodies of water with more food, like lakes and rivers?
Larval (baby) mosquitoes are aquatic insects but they do not breathe water like fish or young dragonflies do. Just like whales they live in the water but breathe air, so they must stay close to the surface or risk drowning. Instead of a blowhole the larvae have a special siphon which they use to suspend themselves from the water's surface tension. Breaking the surface tension with a drop or two of dish soap will kill any larval mosquitoes by not allowing them to breath (drowning them).
In larger bodies of water fish and other predators, like giant water bugs, can easily snap the larvae up as they hang, suspended from the surface. If they attempt to hide on the bottom or in vegetation the larvae risk drowning while waiting for the predator to lose interest.
Here are a few videos that I made to demonstrate the principle. Sorry about the background noise in these videos. Laboratory buildings require substantial ventilation systems for health reasons, and they are pretty loud.