We went to Lake Poway a few weeks ago and collected some lake water (with scum, of course!) from the spot marked by the arrow. We didn't get around to looking at it until a few weeks later, and by then some insect eggs had hatched into larvae.Below is a little guy that was swimming around. The video is only at 4x, and he was a few millimeters long.
It might be a damselfly larva, based on pictures I found by googling. Here's a useful page of other tiny aquatic creatures.
I have to say, baby bugs just aren't as cute as baby mammals.
