London - Pythons and boa constrictors have long been thought to kill by suffocation, cutting off their victims’ air supply.
But scientists have found that, in fact, they cut off the blood supply of their prey, leading swiftly to a heart attack.
Snakes fed anaesthetised rats in a study first bit them, then constricted them with at least two loops, creating two points of pressure around the ribcage or abdomen.
US researchers monitoring the rats’ blood pressure and heart rates watched in “disbelief” as their circulation shut down in seconds and their hearts beat irregularly.
Snake researcher Scott Boback, from Dickinson College in Pennsylvania, suspects that without blood flow to the brain, animals in the snakes’ coils probably pass out before other critical organs begin to fail.
The snakes save energy by easing off the pressure the second they sense their victim’s heart has stopped beating.
Previously, claims that they did not kill by suffocation were considered a fringe view, but this is the first time the hypothesis has been tested in the lab. The study is published in the Journal of Experimental Biology.
Daily Mail