Females’ genitalia bears a highly unusual resemblance to that of males—leading to the myth that they are hermaphrodites. Females have an enlarged, penis-like clitoris through which they urinate, mate and give birth. In place of a vagina, they have a scrotum-like pouch. During birth, the clitoris ruptures to allow young to pass through. The resulting wound takes weeks to heal and is one way to identify a mature female’s gender. This bizarre adaptation may cause females to tolerate the presence of smaller males, who aren’t particularly needed for protection or hunting. Since this social system favors aggression, females produce and pass along high quantities of male hormones and extremely high-energy–content milk to offspring. Cubs are born with their eyes open and well-developed teeth, and begin fighting within minutes after birth. Siblings of the same sex often fight until one is killed—enabling the survivor to receive more food and mature faster.