A group of ravens is called an unkindness. Ravens belong to the same family as crows, but they're of a more robust build and have heavier beaks. They also make a more gutteral croaking sound.
The raven is found from Alaska down into Georgia. It's also found in northern Europe, parts of Asia and northern Africa. It isn't found around human habitations as often as the crow. The raven is a bird of prey that eats the eggs and young of other birds, though it also scavenges. Unlike the crow, it is adept at gliding on thermals and acrobatic displays.