What is the collective noun for a group of crows?

A group of crows is a murder, which sounds like folklore invention but comes from a real written tradition. In the fifteenth century, English hunting manuals such as the Book of Saint Albans listed elaborate terms of venery, the proper words a gentleman was expected to use for groups of animals, and much of the list was as much a display of wit and social polish as a practical vocabulary. That is where an exaltation of larks, a parliament of owls and a murder of crows all come from. Most were never in ordinary speech and survive today mainly in quiz questions and word lists. The crow's term probably reflects the bird's long association with battlefields and carrion, and its habit of gathering in noisy mobs, sometimes around a dead member of its own species. Ornithologists writing scientifically will just say a flock or a roost.

Crows are among the few animals shown to recognise individual human faces and hold on to that recognition for years.