Happy Wonderer

Hey, have any of the Entomologists out there studied how aquatic-based lavae respond to drought?

Here is the story. Last night I noticed that a small (5 cubic foot) fountain that I own was filled with mosquito larvae. I cleaned out the fountain by draining it, laughing gleefuly as I sucked larvae into the siphon (where they were transported to become fertilizer for the blueberries.)

When I had the water mostly drained I noticed that I still had a number of larvae in the little bit of water that I couldn't get, so I waited for the sun to evaporate the rest of the water.

I came back after an hour and saw the damndest thing -- there were three wriggling balls of (apparently) larvae just outside of the edge of the remaining water. Each ball was approx. 1/2" in diameter and consisted of a dense cluster of (very small) individuals. Occasionally new individuals would join the ball as it happened to move in their direction. None of the balls moved very far or very purposefully, but they did move around a bit.

Was this just random behavior of individuals looking for the nearest wet object, or is there some adaptave behavior unique to these critters?

Thanks for ideas.

hw