Pygmy Mole Crickets Use Oar-Like Paddles to Jump Off Water's Surface

Pygmy mole crickets are known to be skilled jumpers on land. But a new study finds that these small insects are good at jumping from the surface of water onto the bank.

Researcher Malcolm Burrows, of the University of Cambridge, UK, noticed this amazing feat of the pygmy mole crickets while having lunch next to a pond in South Africa. On hearing odd noises from the pond, Burrows closely examined it and found the small insects jumping off the water's surface.

He collected samples of the pygmy mole crickets (Xya capensis) and tested them in the lab to figure out how exactly they achieved this feat. Along with his colleague Gregory Sutton, Burrows filmed the insect's jumping skill using a high-speed camera.

Researchers noticed that the pygmy mole crickets have spring-loaded, oarlike paddles on their back legs, which are 4.5 times larger than their front legs. The insect's muscles have a protein called resilin, described as "the perfect elastic". Resilin can store energy for a quick release. They are found in small insects like flies, helping them to beat their wings at a rapid speed, LiveScience reported.

As the oar-like paddles penetrate the water, they fan out. The crickets grab large volumes of water, pushing it downwards, as the insect's body flies upward and out of the water. This technique helps them escape attacks from fish and other insects in the water.

Experts suggest that the makeup of the pygmy mole cricket's legs could be used to build small aquatic robots. "If we want to make small robotic vehicles that move under water, this is how we would have to design propellers or oars," Burrows said in a statement. "We would also have to use a material as good as resilin to impart elasticity, restore shape, and reduce drag."

The findings of the study, "Pygmy mole crickets jump from water", appear online in the Dec. 4 issue of the journal Current Biology.

Check out how the tiny insects jump on water: