I love coming home from work and being greeted by my dogs, Doc and Lavender. Well, and my entire family as well. But there’s just something special about being greeted by your tail-wagging, “it’s been forever since I saw you” best friends!

Did you know that Dogs cry “happy tears” when you come home? This is according to a study inspired by a scientist whose own pup welled up with joy whenever they reunited. It’s well known that dogs have tear ducts designed to flush dirt from their eyes, but the process had never been linked with emotion—until now. Professor Takefumi Kikusui decided to investigate after his poodle had puppies, and he noticed the dog’s face changed when it nursed the babies. It had tears in its eyes. That gave him the idea that oxytocin might be causing the watery flood—and dogs, like humans, may produce tears when they are flooded with emotion. Oxytocin is known as the maternal or “love hormone.” When they added oxytocin to the dogs’ eyes, their tear volume also went up. That finding supports the idea that the release of oxytocin plays a role in tear production when dogs and their people get back together.