If you have a dog, you've probably had an experience like this. You head out of the house, realize you forgot your phone, pop back in to grab it, and your dog greets you as if you've been gone 10 years.
Dogs appear to have no sense of time. Yet that same dog waits lovingly by the door precisely when it's time for the kids to get home from school. What gives? Can dogs tell time or not? What does time even mean to a dog?
That's a tricky question to answer, and what precious little research has been done is, frankly, not all that helpful. But when it comes to the second example above, there probably is a fairly straightforward answer.
"There's a lot of evidence that dogs know when somebody's supposed to come home," says Greg Bryant, a cognitive scientist at the University of California, Los Angeles. "But ...
