We saw these small, shiny, carnivorous insects swimming in their crazy circles on the surface of one of the Gallows Hill ponds. Apparently this movement is defensive, and they can dive down below their usual habitat if further disturbed, trapping a bubble of air to take with them. When on the surface, their divided eyes enable them to see above and below the water level simultaneously, which is pretty cool. Their waxy, water-repellent skin makes them difficult to catch, and the males have suckers on their front legs to help them hold on to the slippery female during mating. Studies of their fascinating, complex group movement dynamics are hoped to give insights into how groups of robots might operate together.