Mockingbirds are very aggressive. They don't take kindly to birds that invade their territory, and will guard it vigilantly. They feed off of a variety of things including insects, crustaceans, and fruits. Mockingbirds nest in shrubs and trees and lay 2-6 eggs at a time. They may raise multiple broods in a season.
Mockingbirds are extremely vocal, can mimic many other bird species, and continue to add new songs throughout their lifetime. An adult male may learn up to 200 songs throughout its life. One recording of a Northern Mockingbirds showed that it could imitate the calls of 36 other bird species. They sing both night and day, depending on if they have a mate or not. Females also sing, though they are less loud.