Humans love dogs and they love us back. Scientists think humans have had dogs since we were hunters and gatherers. What turned into dogs were likely wolves that became somewhat tame. They liked eating the scraps we threw away. At the time they were useful to us as watchdogs. Over time wolves changed to become the dogs we know today. Recently scientists have found that dogs have a "love chemical" for people. It's the same chemical we have for each other and for them. No wonder we love our dogs!