There are usually 4-6 pups born in each litter. Pups are born inside a den. A den is sometimes a small cave or a hole dug out of the ground. The den must be big enough for the mother and her pups. It shelters them from the weather and protects the pups from other animals that may want to hurt them.
Packs sometimes use the same den year after year.
At other times they make or find a new den each year. The gestation period is about 63 days. At birth, they weigh only 1 pound and their eyes are closed. Pups grow quickly. About 12 to 15 days after they are born they open their eyes.