Any of various venomous snakes, of the family Crotalinae, found in Asia and the Americas, with a deep pit or fossa on either side of the head that enables them to detect prey by infrared
Any of various venomous snakes of the family Crotalidae, such as a copperhead, rattlesnake, or fer-de-lance, characterized by a small sensory pit below each eye. Any species of viper (subfamily Crotalinae) that has, in addition to two movable fangs, a heat-sensitive pit organ between each eye and nostril which together help it accurately aim its strike at its warm-blooded prey. Pit vipers are found from deserts to rain forests, primarily in the New World. They may be terrestrial, arboreal, or aquatic. Some species lay eggs; others produce live young. See also bushmaster, copperhead, fer-de-lance, moccasin, rattlesnake