There are 11 known species of skunks, some of which are also commonly referred to as polecats. The most common varieties in the United States are two species of spotted skunks, which are both members of the genus Spilogale, and the striped skunk, which is scientifically described as Mephitis mephitis. These skunk types, as well as most others, are nocturnal and primarily feed upon birds, insects, worms, rodents, eggs, and plant matter. They typically live as groups or families in dens formed from underground burrows, but may also inhabit barns, woodpiles, haystacks, rocky crevices, and similar locales.