The true crows are large passerine birds that form the genus Corvus in the family Corvidae. Raven is the common name given to several larger-bodied members of the genus Corvus—but in Europe and North America the Common Raven is normally implied.

The Common Crow is a big, all black (glossy) bird about 17 to 20 inches long with a strong thick build and a short, compressed bill. The Fishing Crow is a smaller and even darker version of this social bird family. Crows are scavengers and will eat a wide variety of things including: insects, frogs, small snakes, eggs, mice, dead animal carcasses and newly planted crops. These highly intelligent birds are very social and the flock is in constant, noisy communication with each other, making hunting or capturing crows very difficult.

As a group, the crows show remarkable examples of intelligence, and Aesop's fable of The Crow and the Pitcher  shows that humans have long viewed the crow as an intelligent bird. Crows and ravens often score very highly on intelligence tests. Certain species top the avian IQ scale.

Like blackbirds, crows and ravens will gather in massive feeding flocks at certain times during the year, joining with other flocks to form enormous roosts numbering in the thousands of pest birds.

When crows and ravens are in their flocking phase, thousands of these very noisy pest birds can literally overwhelm trees or buildings in an area, creating a tremendous amount of noise and harassing both people and animals in the area. Other crow and raven problems occur when there is a large scale buildup of their feces which can lead to structural damage as the uric acid in the pest bird droppings can corrode stone, metal and masonry. As with other pest bird species, the bacteria, fungal agents and ectoparasites found in crow droppings and nesting materials pose a serious health risk. Crows and ravens are most often the source of agricultural bird problems due to their fondness for corn and other crops, especially when newly planted.