The eastern hog-nosed snake (Heterodon platirhinos), also known as the spreading adder and by various other common names, is a species of mildly venomous rear-fanged snake in the family Colubridae. The species is endemic to North America. There are no subspecies that are recognized as being valid. Geographic range H. platirhinos is found from eastern-central Minnesota, and Wisconsin to southern Ontario and extreme southern New Hampshire, south to southern Florida and west to eastern Texas and western Kansas. Habitat Studies have shown that H. platirhinos prefers upland sandy pine-forests, old-fields and forest edges. Like most of the genus Heterodon, the Eastern Hognose Snake prefers dry conditions with loose soil for burrowing purposes. These loose soils are preferable habitat components for nesting and egg laying. At the northern end of their range, they have been found to prefer developed lands as their desired habitat followed by mixed forests dominated by Hemlock trees. Based on a study in Canada, the average home range size is about 40 hectares. Some individuals will travel outside of their home range in search of mates and nesting sites. Description and etymology The average adult H. platirhinos measures in total length (including tail), with females being larger than males. The maximum recorded total length is . The generic name Heterodon is derived from the Greek words heteros meaning "different" and odon meaning "tooth". The specific name platirhinos is derived from the Greek words platys meaning "broad or flat" and rhinos meaning "snout". The most distinguishing feature is the upturned snout, used for digging in sandy soils. The color pattern is extremely variable. It can be red, green, orange, brown, gray to black, or any combination thereof depending on locality. Dorsally, it can be blotched, checkered, or patternless. The belly tends to be a solid gray, yellow, or cream-colored. In this species the underside of the tail is lighter than the belly. Venom Although H. platirhinos is rear-fanged, it is often considered nonvenomous because it is not harmful to humans. Heterodon means "different tooth", which refers to the enlarged teeth at the rear of the upper jaw. These teeth inject a mild amphibian-specific venom into prey. The fangs receive the venom from the snake's Duvernoy's gland. Bitten humans who are allergic to the saliva have been known to experience local swelling, but no human deaths have been documented. Common names Common names for H. platirhinos include eastern hog-nosed