Every dog owner knows the look: It seems to say “Take me with you” or “Why can’t I sit on the sofa?” Scientists have found the reasons behind that hard-to-resist facial expression, known as puppy-dog eyes. 

In 2019, scientist Anne Burrows and her team discovered that, over time, dogs developed a muscle above their eyebrows that makes their eyes open wider. And in a study released this year, the researchers found that dogs move their facial muscles in the same way we do. Burrows says this helps pups communicate with us. 

“Dogs and humans can accurately understand one another’s facial expressions,” she says. “They get us in a way that no other animal does.”