Do all mammals have periods?

View image of Eastern elephant shrews (Elephantulus myurus) menstruate (Credit: Klein & Hubert/NPL) It all comes down to how much control the mother animal has over her own womb, according to Deena Emera of Yale University in New Haven, Connecticut. read more

Female mammals all have some sort of estrus cycle - periods of fertility and infertile periods. However, very few of them are like humans'. Humans MENSTRUATE which involves discharge at a time of infertility while the lining of the uterus breaks down and is expelled. read more

Menstruation in mammals is the shedding of the uterine lining (endometrium). It occurs on a regular basis in sexually reproductive-age females of certain mammal species. Though there is some disagreement in definitions between sources, menstruation is generally considered to be limited to primates. read more