Boa skin feels the pulse of the victim

Scientists believe that it is important not to boa force with which they squeeze their prey, and the amount of energy expended in the "deadly embrace". "The process of compression is energetically costly and potentially dangerous action," the researchers wrote Dickinson College. "From this it follows that the snakes, energetically advantageous to be able to determine when production is no longer able to defend himself and escape».

Changing the time and effort spent on compression seems innate skills in these animals, but studies show they can improve their natural abilities.

In the wild, boa tend to compress the rat for 20 minutes, after which it eats its prey. Scientists conducted an experiment by offering boa is already dead, but still warm rat with an artificial heart. It was also the compression sensor.
The researchers recorded the first time such a lasting impact on the victim. BoA did not start the meal to as long as scientists have not stopped the rat heart.

Such skills have not only caught snakes, boas are born in captivity and never uses a "live" foods in the experiment reacted as well.

"The ability to respond to a heartbeat is innate, and the strength of the response depends on the experience," the authors write.
Researchers believe that the very sensitive skin snake could develop as an alternative to the feet, for a better perception of the environment, and the snake just used this sensitivity to kill prey.