ABSTRACT
Thermal detectors have been in use for perhaps millions of years in target locating systems by two families of snake who use the temperature difference between their prey and its surroundings to locate and capture the small animals on which they feed. Nature has given snakes like the rattlesnake and the pit viper, pit organs that act like small pinhole cameras capable of imaging infrared light in the eight to fourteen micron wavelength region, 1 giving these snakes a marked advantage over their prey. It has now been established that the snakes’ sensors are in fact thermal detectors. In 2300 BC, the Greeks considered tour maline a magical material because, when heated, it produced a charge which shocked the unwary. This effect was pyroelectricity, and the observation is one of the earliest on record.
