Squirrel simulates death after noticing human presence; understand what tanatosis is

For us, “pretending to be dead” in the popular saying means, mainly, that dissimulated person or who pretends to be ignorant to escape from some situation.

In the animal kingdom, this strategy is taken a little more seriously. This week, a squirrel went viral on social media for trying to play dead after noticing a human presence inside a house.

I have died. I am dead. Here I shall lay, Call the police. pic.twitter.com/oUhCOdOSRd

— kk ϻʳ.𝓡𝓪𝔂 UNOFFICIAL (@kkMrRay) June 3, 2023

In the case of the animal, the clumsy “performance” did not work out as well as he imagined. The little squirrel squirmed, crawled and even “pretended” to be hit by a broom – attempts that didn’t convince anyone.

Despite the funny scene, the act of pretending to be dead is a strategy used by several species to escape predators. The technique, called thanatosisis often the last chance for survival for many animals.

What is thanatosis

In an interview with CNN biologist Vitor Filiputti explains how the mechanism is performed and its importance for the survival of the animal.

“Thanatoses is, initially, a resource used to escape predators. The technique is also called tonic immobility because it results in muscle stiffness to make the pretense more real,” says the biologist.

The strategy often works because predators do not usually feed on prey that is already dead – mainly because they think that they may have died of some disease.

According to the biologist, there are two models of thanatosis: pre- and post-contact.

“Pre-contact thanatosis happens when the prey perceives the approach of some threat and prepares itself before the attack, already showing itself dead for the predator to give up. Post-contact happens when the predator manages to capture the prey and, before being actually killed, the animal simulates death so that it does not end up being devoured”, explains Vitor.

The professional explains that the pretense can be so well done that some species even alter the metabolism.

“Some bodily functions of the individual, such as heartbeat, for example, reduce naturally. It is a natural reaction of the body, the heartbeat even drops until it is close to zero, ”he says.

Among the animals that have thanatosis, among the main ones are possums, guinea pigs, some species of rabbits and even fish.

Beyond the quest for survival

Animals do not pretend to be dead just to escape a possible predator, but also for food and even reproduction.

The biologist gives some examples. “Garden spiders have a really cool strategy for reproducing. The males of the species gather a large amount of food to attract the female and, when she gets close, he plays dead. While she is focused on feeding, the male “wakes up” and promotes mating.”

In addition to this mating strategy, there is also a thanatosis technique to avoid reproduction, as explained by Vitor.

“There are dragonflies that, during the mating period, release pheromones that attract a large number of males. The female often ends up getting tired during the process, so she stiffens up and plays dead to scare off the males,” she says.

Last resource

Despite being a technique that is often effective, the biologist points out that it is used as the last chance to survive.

“Thanatoses, for most species, is considered a last resort. So it’s not something the species does constantly. She will use the resource at that moment when she thinks: ‘look, I can’t escape anymore”.