Sometimes two girls raise babies together.

Grizzly bears mate during the summer, but the female does not become pregnant immediately, instead delaying embryo implantation until hibernation. If her caloric intake over the summer was sufficient, she will give birth in mid-winter, often to twins. Mother and cubs remain in the den for a few more months, leaving as spring arrives. At this point, the female will sometimes form a friendship with another mother and share in childcare.

Sometimes two boys parent as a team.