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.
Human placentophagy
Maternal placentophagy is defined as "a mother’s ingestion of her own placenta postpartum, in any form, at any time". Of the more than 4000 species of placental mammals, most, including herbivores, regularly engage in maternal placentophagy, thought to be an instinct to hide any trace of childbirth from predators in the wild. The exceptions to placentophagy include mainly humans, Pinnipedia, Cetacea, and camels.