As children grow older, they begin to map number words to collections of objects, for example, “two socks,” and by age 2, many children can subitize up to three items, and 4- and 5-year-old ...

Crows can vocally count up to four. The intelligent birds recognize and react to numbers in a process similar to that of human cognition, according to a new study.

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.