Crows can count... out loud! They do so similarly to human toddlers who are learning to tally things up. A neuroscientist trained birds to produce a number of calls in response to random visual cues.

To me, crows are the smartest birds in the world. As a kid I never could outsmart them. I had a hand call but didn’t really know what I was doing. Years later I finally learned the system. Like I say, ...