Garter snake is a common name for generally harmless, small to medium-sized snakes belonging to the genus Thamnophis in the family Colubridae. Native to North and Central America, species in the genus Thamnophis can be found from the subarctic plains of Canada to Costa Rica. With about 35 recognized species and subspecies, garter snakes are highly variable in appearance. They generally have large round eyes, round pupils, a slender build, keeled scales, and a pattern of longitudinal stripes that may or may not include spots (although some have no stripes at all). They also vary significantly in total length from as short as 18″ to as long as 51" (45-130cm). Garter snakes have complex systems of pheromonal communication. They can find other snakes by following their pheromone-scented trails. Male and female skin pheromones are so different as to be immediately distinguishable. However, male garter snakes sometimes produce both male and female pheromones. During the mating season, this ability fools other males into attempting to mate with them. This causes the transfer of heat to them in kleptothermy, which is an advantage immediately after hibernation, allowing them to become more active. Male snakes giving off both male and female pheromones have been shown to garner more copulations than normal males in the mating balls that form at the den when females enter the mating melee. A snake hatch can include as many as 57 young. (Source: Wikipedia.org, CC BY-SA)