Pit Viper
Crotalinae (subfamily)
A diverse group of vipers defined by heat-sensing facial pits, including rattlesnakes, copperheads, and Asian bamboo vipers.
- Venomous?
- Venomous
- Adult length
- 0.5-2.5 m (1.6-8 ft), varies greatly by species
- Range
- Americas and Asia, temperate to tropical regions
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Overview
Pit vipers form a large subfamily of the viper family distinguished by paired heat-sensing pit organs located between the eye and nostril, allowing them to detect warm-blooded prey in darkness. This subfamily includes rattlesnakes, copperheads, cottonmouths, and numerous Asian species such as bamboo pit vipers.
Found throughout the Americas and Asia, pit vipers occupy an enormous range of habitats, from deserts to rainforests to high mountain slopes.
How to identify it
- Broad, triangular head clearly distinct from a narrower neck
- Heat-sensing pit organ visible between each eye and nostril
- Vertical, elliptical pupils in most species
- Heavy, thick body typical of ambush predators, though body shape varies by species
- Distinguished from other vipers and colubrids specifically by the facial heat-sensing pits
Habitat & range
Occupies an extremely broad range of habitats across the Americas and Asia, including deserts, grasslands, forests, swamps, and mountain slopes, depending on the specific species.
Behavior, diet & reproduction
Most are ambush predators, using heat-sensing pits to detect warm prey even in complete darkness, striking rapidly then tracking envenomated prey by scent. Diet varies by species but often includes rodents, birds, amphibians, and other small vertebrates. Reproductive strategies vary, with many species giving birth to live young.
Frequently asked questions
What defines a pit viper?
The presence of heat-sensing pit organs between the eyes and nostrils, used to detect warm-blooded prey.
Which snakes are pit vipers?
Rattlesnakes, copperheads, cottonmouths, and many Asian species such as bamboo pit vipers all belong to this subfamily.
Are all pit vipers dangerous?
Most possess medically significant venom, though potency and danger to humans vary widely between species.
How do heat-sensing pits work?
They detect subtle infrared radiation from warm-blooded prey, allowing accurate strikes even in total darkness.
Pit Viper guides
In-depth guides for identifying and understanding Pit Viper.
