The crow genus makes up a third of the species in the family Corvidae. The members appear to have evolved in Asia from the corvid stock, which had evolved in Australia. The collective name for a group of crows is a 'flock' or a 'murder'.
Recent research has found some crow species capable of not only tool use, but also tool construction. Crows are now considered to be among the world's most intelligent animals with an encephalization quotient equal to that of many non-human primates.
In medieval times, crows were thought to live abnormally long lives. They were also thought to be monogamous throughout their long lives. They were thought to predict the future, to predict rain and reveal ambushes. Crows were also thought to lead flocks of storks while they crossed the sea to Asia.