Menstruation (mammal)
Menstruation in mammals is the shedding of the uterine lining (endometrium). It occurs on a regular basis in uninseminated sexually reproductive-age females of certain mammal species.
Female
Female (♀) is the sex of an organism, or a part of an organism, that produces non-mobile ova (egg cells). Barring rare medical conditions, most female mammals, including female humans, have two X chromosomes. Female characteristics vary between different species with some species containing more well defined female characteristics. Both genetics and environment shape the prenatal development of a female.