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Where are heat-sensing pits located on pit vipers?

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timber rattlesnake — snake Timber rattlesnake (*Crotalus horridus*).

On pit vipers, the heat-sensing organs are located on the head, specifically positioned just below and behind the nostril. These facial pits are also described as being situated between each eye and the nostril.12

These specialized organs consist of two chambers separated by a thin membrane that is densely supplied with nerve fibers and blood vessels, allowing the snakes to detect minute temperature differences in their environment. This infrared-sensing capability enables them to accurately strike at warm-blooded prey in the dark.12