The Fascinating Reproductive Habits of African Pouched Rats and Bomb Detector Rats

Female African pouched rats have been found to seal off their vaginas, preventing themselves from breeding. Researchers observed that some females had a smaller uterus and a fused vaginal opening, and their urine had a different chemical composition than their nestmates who were actively breeding. The phenomenon is speculated to be a result of one female manipulating others to stop reproducing, contributing to the care of the dominant reproducing female. This trait is unusual for mammals, and the hormones associated with breeding cycles in other rodents did not seem to determine which females were open for business in these giant African pouched rats.