Frogs are sometimes described as not hopping, nor jumping, but “skittering” across the surface of water, almost appearing to levitate above it.

But what does this skittering actually involve? Researchers have captured cricket frogs on camera to figure it out.

“Skittering is not actually a well-defined word for this behaviour,” says Talia Weiss, a graduate student at Virginia Tech, USA, and first author on a paper published in the Journal of Experimental Biology.

“One naturalist used it to describe a ‘jumping on water’ behavior in frogs in 1949, and since then, it’s been used for this type of locomotion in all the following literature.”

Frogs skitter very quickly, making it hard to assess exactly how they’re moving.

The researchers recorded high-speed video of 15 northern cricket frogs (Acris crepitans) as they leapt and skittered across water.

They found that the frogs were not actually staying above water in their skitters – instead, they were completely submerged when landing from and launching into a jump.

This suggests that the frogs might be more accurately described as “porpoising”, which is usually used to describe how porpoises and dolphins move.

“It’s fascinating how easily we can be fooled by fast animal movements,” says lead researcher Professor Jake Socha, also from Virginia Tech.

“Here, we’re fooled by a frog that appears like a skipping stone, but is actually jumping and dunking multiple times in a row.

“Frogs are great jumpers, but most of them don’t exhibit this porpoising behaviour, and we still don’t know why. Is there something special about the frog’s leap, or is it simply a matter of small body size?”