Hognose snake is a common name for several unrelated species of snake with upturned snouts, classified in 2 colubrid snake genera and 1 pseudoxyrhophiid snake genus. They include the following genera: Heterodon, which occur mainly in the United States and northern Mexico Leioheterodon, the hognose snakes native to Madagascar Lystrophis, the South American hognose snakes. The North American Heterodon species are known for their habit of thanatosis: playing dead when threatened. Species Genus Heterodon: Mexican hognose snake, Heterodon kennerlyi (Kennicott, 1860) Gloyd's hognose snake, Heterodon nasicus gloydi (Edgren, 1952) Western hognose snake, Heterodon nasicus (Baird & Girard, 1852) Eastern hognose snake, Heterodon platirhinos (Latreille, 1801) Southern hognose snake, Heterodon simus (Linnaeus, 1766) Genus Leioheterodon: Speckled hognose snake, Leioheterodon geayi (Mocquard, 1905) Malagasy giant hognose snake, Leioheterodon madagascariensis (Duméril & Bibron, 1854) Blonde hognose snake, Leioheterodon modestus (Günther, 1863) Genus Lystrophis: South American hognose snake, Lystrophis dorbignyi (Duméril, Bibron & Duméril, 1854) Jan's hognose snake, Lystrophis histricus (Jan, 1863) Lystrophis matogrossensis (Scrocchi & Cruz, 1993) Lystrophis nattereri (Steindachner, 1867) Tricolor hognose snake, Lystrophis pulcher (Jan, 1863) Ringed hognose snake, Lystrophis semicinctus (Duméril, Bibron & Duméril, 1854) Description The hognose snakes' most distinguishing characteristic is their upturned snout/Rostral scale, which aids in digging in sandy soils by using a sweeping, side to side motion. They also like to burrow in masses of humus. Lieoheterodon species are known to dig up the eggs of lizards. Hognose snakes are extremely variable in color and pattern. Heterodon nasicus and H. kennerlyi tend to be sandy colored with black and white markings, while H. platirhinos varies from reds, greens, oranges, browns, to melanistic (i.e. black) depending on locality. They are sometimes blotched and sometimes solid-colored. Leiohetereodon geayi is a brown or tan colored snake with dark speckling on it. There are also many different morphs when bred in captivity. Behavior When threatened, hognose snakes will hiss, flatten their necks and raise their heads off the ground like cobras. They sometimes feign strikes, but actual Heterodon bites are very rare. This behaviour has earned them local common names such as "puff adder", "blowing adder", "flathead", "spreadhead", "spreading adder" or "hissing adder". Note: For Heterodon, "puff adder" is a common name inconsistent with established usage. "Puff adder" is the accepted common name of Bitis arietans, an unrelated, dangerously venomous African species of viper, which incidentally does not flatten its neck in any threat display. If this threat display