Monotremes are egg-laying mammals of which the most well- known example of a monotreme is the platypus. The word monotreme stems from a concatenation of the Greek words μονός, monos (“single”) and τρῆμα, trema (“hole”). This word for “single opening” refers to a monotreme’s cloaca. Unlike other mammals, the urinary, defecatory, and reproductive systems of the monotreme all open into a single duct known as the cloaca.
Echidnas, also known as spiny anteaters, are monotremes found in Australia and New Guinea. During the mating season which occurs from late June and extends through September, hopeful males form what is known as a love train behind females. These lines may be up to ten animals long with the smallest and youngest echidnas forming the end of the train. This mating ritual is known as ‘trailing’.
The Taranga Zoo in Sydney, Australia captured video of this quirky love fest. When breeding season arrives, the female echidna releases a pheromone which will attract a line of suitors. These hopeful suitors will trail behind the female for up to several days. Eventually, the female will stop walking and accept the male that is behind her. By the way, a baby echnida is known as a puggle.