Abstract
The whirligig beetles are a family (Gyrinidae) of water beetles that usually swim on the surface of the water if undisturbed, though they swim underwater when threatened. The name "whirligig" comes from this small beetle's ability to spin quickly on the surface of the water, which is used as a survival strategy.
Whirligig beetles are fully aquatic and cannot walk well on land because their middle and hind legs are modified into a flipper-like shape. Whirligig beetles possess unique eyes which are split into overwater and underwater parts.
The adults carry an air bubble under their elytra, and can submerge for long periods if they want to. Mostly they move around on the surface in groups.
Both larvae and adults are active predators. In this contribution some observation and experiments in school aquaria are presented.