Do rattlesnakes have a pair of "eyes" that can sense heat sources?

Do you know about the Sidewinder missile? In the world's military history, it is called the "air killer". The reason why it is so famous is not only because of its powerful lethality in air combat, but also because of its excellent anti-interference ability. It can bite the opponent in a complex battlefield environment and hit the target accurately. Why does this missile have such a high hit rate? The answer lies in its name.

The Sidewinder missile relies on the "Sidewinder heat-sensing" infrared detection technology to lock on to the target, which is a way of achieving guidance by detecting the infrared radiation signals emitted by the target. When the missile approaches the target, its infrared detector will receive the infrared radiation signals emitted by the target and adjust the flight direction of the missile according to these signals until it successfully hits the target. This guidance method gives the Sidewinder missile a high hit rate and anti-interference ability.

Sidewinder missile mounted on a fighter jet. Image source: Internet

So, how come rattlesnakes have infrared detection technology? This is all thanks to the rattlesnake's thermal receptors - "thermal eyes". Snakes such as rattlesnakes and pit vipers have "thermal eyes" that grow between the eyes and nostrils, in a place called the cheek pit. The cheek pit is generally 5 mm deep and only 1 cm long. This cheek pit is in the shape of a trumpet, with the trumpet mouth facing forward obliquely, and is divided into two parts, the inner and outer parts, by a thin film in the middle. The inner part has a thin tube that connects to the outside world, so the temperature inside is consistent with the temperature of the surrounding environment where the snake is located. The outer part is a heat collector. If there is a hot object in the direction facing the trumpet mouth, infrared rays will pass through here and irradiate the outer side of the film. Obviously, this is higher than the temperature on the inner side of the film, and the nerve endings covered on the film can sense the temperature difference and generate bioelectric current, which is transmitted to the snake's brain. The snake knows where there is a hot object in front. This type of moving object is often a small warm-blooded animal, and the rattlesnake's brain will issue a corresponding "instruction" to capture the prey.

The hot eyes on the head of a rattlesnake. Image source: Internet

The thermal sensing principle of the Rattlesnake Thermal Eye System has also been successfully applied in medicine. People have designed medical infrared thermal imagers, which use similar equipment to detect infrared rays emitted by the human body and convert them into clearly visible thermal images. This thermal image can intuitively reflect the temperature distribution of different parts of the human body. This is of great significance in medical diagnosis. For example, when inflammation occurs in a part of the human body, it is usually accompanied by an increase in temperature. Thermal imaging technology can accurately detect these abnormal temperature areas, thereby helping doctors to make early diagnoses. In addition, it can also be used to monitor the blood circulation of the human body, because the flow and distribution of blood will affect the local temperature. Infrared thermal imagers can be used for disease diagnosis and physical therapy. It can also measure body temperature quickly and contactlessly in public places. The bilirubin level in the blood of newborns is detected by infrared rays of a specific wavelength so that jaundice problems can be discovered and treated in a timely manner.

In-depth research on the thermal sensing principle of the Rattlesnake Thermal Eye System has provided valuable inspiration and ideas for the development and innovation of many medical devices. Researchers can design more accurate and efficient detection instruments based on these principles, further improve the accuracy and effectiveness of disease diagnosis and monitoring, and bring new breakthroughs and developments to the medical field. Of course, in actual medical applications, the thermal sensing principle of the Rattlesnake Thermal Eye System needs to be further developed and improved in combination with modern technology so that it can better adapt to the special needs and standards of the medical field and play a greater role in human health.