You Won’t Believe How This Beetle Walks on Water

Scientists observed a beetle walking upside-down on the undersurface of a pool of water.

After dark, the Watagan Mountains in New South Wales, Australia, can appear otherworldly to anyone with a headlamp. But things turned stranger than usual in 2015 when John Gould, a behavioral ecologist at the University of Newcastle in Australia, was surveying sandpaper frogs in the forests’ ephemeral pools for his dissertation. Dr. Gould was crouching upon a pool, seeking frogs, when he saw a pea-sized bug that he thought had fallen into the water. As he peered closer, Dr. Gould realized he was not watching a right-side-up bug struggling to escape the water, but an upside-down beetle in full control of its life and current situation. It skittered along the undersurface of the water as if in a parallel world, the kneeling Dr. Gould beneath him. The surface of the pool was immaculately still, nary a wind ripple in sight, and Dr. Gould pulled out his phone to record the water scavenger beetle’s nonchalant ceiling crawl. Because the footage was unrelated to his research, Dr. Gould stored the beetle video in his files and did not return to it for several years as he finished his doctorate. In June at last, Dr. Gould and Jose Valdez, a wildlife ecologist at the German Centre for Integrative Biodiversity Research in Leipzig, published the first detailed documentation of this behavior in beetles in the journal Ethology.