A Face Built for the Dark
Between the Malabar pit viper's nostril and its eye, on each side of its head, sits a small depression called the loreal pit. It looks unremarkable. It is anything but. This pit is a heat-detection organ, lined with a membrane packed with temperature-sensitive receptors that can register differences as small as 0.003 degrees Celsius. The snake does not see heat the way a thermal camera does, it senses it, the way your hand senses the warmth of a flame before it touches you, but with a precision your hand could never match.
