World-first acrobatic Beetle: it can run upside down under water

Acrobatic Beetle! A beetle that can walk upside down under water has been observed for the first time in Australia. It was a scientist who discovered the creature by accident. Possibly the beetle wants to escape predators with this unique way of walking.

It was Ph.D. student John Gould who accidentally discovered the beetle during frog research in the Watagan Mountains. Gould was intently studying a pool of water—looking for tadpoles—when he suddenly saw some kind of swimming insect. Only moments later did he realize that it was a beetle walking beneath the surface of the water.

“The moment I realized the beetle was moving across the underside of the water’s surface, I knew I had found something very bizarre,” Gould told Live Science. “The beetle walked casually along the underside of the water’s surface with ease while upside down.”

The animal was also able to rest against the surface as if it were against a glass pane: “That means that it can remain on the water surface without consuming energy. This is in contrast to large animals that move over the surface of the water, such as lizards, which have to keep running to avoid sinking through the surface.”

How the acrobatic Beetle walk upside down?

Gould’s team suspects that the air bubble that sits on the beetle’s abdomen is what allows the animal to perform such a unique feat. With the air bubble, the animal could push itself to the surface of the water. In addition, the beetle has small, hair-like projections that can create even more air bubbles. This allows it to move over the water “without breaking the surface tension of the water”, and thus to ‘fall’.

Further research is needed to confirm this thinking. It is also not yet clear why the beetle performs such acrobatic stunts. Scientists suspect that the insect mainly wants to avoid dangerous predators at the bottom of the pool.