Why do dogs shake off water near us? Scientists have finally discovered the answer.

People and Dogs have lived side by side for thousands of years: during this time, these animals have earned the reputation of being man's best friend, and we know a lot about their behavior. Most dog owners have also noticed that after a bath, dogs come over to people and shake off the water, splattering their owners' clothes. But why does this happen? Researchers have found the answer, as reported by Live Science.

A team of scientists from Harvard Medical School has finally determined why dogs shake themselves dry in a new study. The results indicate that the "wet dog shake" occurs due to a receptor in the skin of mammals known as C-LTMR. This receptor causes pets, including cats, dogs, and even mice, to perform a remarkably consistent shake when droplets of liquid stimulate the area at the back of their necks.

According to co-author of the study, Dave Zhang, it turns out that animals shake with the same frequency and a similar pattern of turns: three back-and-forth shakes at a time. Previously, no one knew which specific receptors and nerves were responsible for this behavior, but now the mystery has been solved.

In their research, the scientists used new genetic tools that allowed them to identify the "culprit" behind the shaking. Initially, the team created genetic mutations in mice that disabled either the channels in skin receptors that detect mechanical forces or the receptors that sense changes in temperature. The results showed that mice unable to sense temperature still shook off water when it landed on their necks. However, mice without mechanoreceptor channels did not shake.

Next, the researchers focused on mechanoreceptors, monitoring their activity. As a result, they were able to narrow down the suspects to three receptors, each of which responds to very light touch.

Subsequently, the scientists employed a technique known as optogenetics to activate specific receptors in the skin using light. This allowed them to stimulate individual types of nerves without any liquid stimulation.

The results were clear: when the type of nerve known as low-threshold mechanoreceptor C-fibers (C-LTMR) was stimulated, the mice shook. To verify the study's findings, the researchers engineered mice without C-LTMR and discovered that they shook 58% less than normal mice when sprayed with water.

According to Zhang, this receptor has long remained a mystery to science. For the past 80 years, researchers have suspected that these receptors create ticklish sensations; however, it was unclear how exactly animals experienced this stimulus. Interestingly, in humans, related mechanoreceptors called C-mechanoreceptors have been linked to pleasant, gliding touches on the skin.

It is known that C-LTMR transmits signals from the underfur follicles of furry animals, so the team believes that they specialize in detecting tiny trembling stimuli, such as crawling parasites or drops of water.