This NXT paddles around in a swimming pool, detects insects floating on the water, then zaps them with insecticide. The project is incredibly well-documented here.
There are eco-friendly and child-friendly insecticides on the market. (I hope this NXT is using such a product).
Comments
While I've given thought to making a water-based robot, the thought of my Brick tipping in keeps me from doing it... maybe one day.
Jim