Scientists Study the Wet-Dog Shake

Anyone who has had a wet dog shake nearby has suspected he ends up wetter than the dog. There’s a reason why dogs shake dry rather than drip dry. 

Researchers at Georgia Tech used high-speed cameras to film dozens of wet animals, from mice to bears. Watching them shake in slow motion revealed they shook 70 percent of the water off their coat in just a fraction of a second.

Although fur is great for keeping animals insulated, when it gets wet, surface tension traps water next to an animal’s skin. In cold weather, that can lead to hypothermia. Shaking is more efficient at getting the water off than evaporation, researchers found.

And not all shakes are created equal. Turns out, furry mammals of different sizes adjust their shaking speed to get as dry as possible using the least amount of energy. That means the smaller the dog, the faster it shakes to dry. Additionally, researchers found that the loose skin that whips around as the animal changes direction is crucial to the efficiency of the shaking.

There is a reason behind the research: Scientists think their findings can lead to technology for instruments like camera lenses or solar panels that need to stay dry but are in hard-to-reach places.