GARTER SNAKE

any of more than a dozen species of snakes constituting the genus Thamnophis, in the family Colubridae. They have a striped pattern suggesting a garter: typically, one or three longitudinal yellow or red stripes, between which are checkered blotches. Forms in which the stripes are obscure or lacking are often called grass snakes. Authorities differ as to the number of species, since garter snakes show only slight differences in scalation but considerable geographic differences in coloration. From Canada to Central America they are among the commonest serpents: every vacant lot harbours a few, and the name garden snake is appropriate. Western forms are more water-loving than eastern forms. Garter snakes are smallusually under 60 cm (24 inches) longand quite harmless. If disturbed they usually hide the head and writhe the tail while discharging a foul secretion from the anal gland; some will strike. Among the more aggressive forms is the common garter snake (Thamnophis sirtalis), North America's most widely distributed reptile. The ribbon snake (T. sauritus), small and slender, is a strongly striped form. Garter snakes live chiefly on insects, earthworms, and amphibians; the ribbon snake is especially fond of frogs. All are rather gregarious before breeding and before hibernating.