around the world

Not sparing his stomach: suicidal animals

Why Animals Commit Suicide

What animals are capable of suicide and why they do it, 

Ants

theguardian.com

Recently, entomologists discovered a new species of ants in the rainforests of Borneo , which explode to destroy the rival. In the battles for the territory, Colobopsis explodens ants explode, splashing the enemy with their insides and poisonous mucus.

It can kill or at least slow down the enemy. For the ant itself, however, this turns out to be fatal.

This behavior scientists explain the antisociality of the ants – for the sake of the prosperity of the colony they are able to sacrifice their lives.

“The colony of ants can not be regarded as a human family – it’s a superorganism where every ant acts as a separate cell in the body with its own role,” explained entomologist Alice Lachini.

However, not all ants explode. Those of them, whose dimensions allow to plug their heads into the anthill, act as passive defenders, while smaller ants-kamikaze attack the enemy. Similarly, other types of ants also act, for example, during the flood defending the anthill from flooding.

Termites

There are also death row among the termites Neocapritermes taracua, which similarly protect their colony from enemies. So, if there are strangers next to the termite, old females of Neocapritermes taracua begin to attack them.

R. Hanus / theguardian.com

At first the jaws go into action, but if the enemy does not retreat, the termite females use secret weapons. At the junction of the chest and abdomen, in all female workers, two reservoirs with a bluish substance appear in the old age – a crystalline protein. And under them are the salivary glands, which, when necessary, enter into a chemical reaction with the protein. As a result, termite explodes and sprinkles with the toxic liquid of the enemy, which soon dies.

Mice

Normally, mice and rats, having smelled a cat nearby, flee. However, in some cases, they not only do not run away, but also go straight to the clawed claws of a predator. This behavior is due to toxoplasmosis. Toxoplasma is a parasite, the main hosts of which are representatives of the cat family.

theguardian.com

Various types of warm-blooded animals act as intermediate hosts. Mice and rats the parasite makes it behave so that the cat can eat them – then toxoplasma will get into her body.

Toxoplasma can cause personality changes in people.

They, too, are pushing for more risky behavior, as well as slowing the reaction rate, causing neuroticism, a sense of anxiety and insecurity. In addition, scientists noted the role of toxoplasmosis in the development of schizophrenia and paranoia.

Bees

According to popular belief, honey bees are killed by stabbing the victim. In fact, this does not always happen. The point is that the tip of the bee stings jagged like a harpoon.

theguardian.com

Getting into the elastic skin of a mammal, it gets stuck in it and the attempt to fly away costs the bee of life – trying to free itself, it just pulls out the stinger together with part of the internal organs. However, if a bee stings another insect, it has all the chances to survive – their body is covered with inelastic chitin, from which the bee is able to extract the sting without endangering life.

And for the wasps, an attack on someone else is completely safe – their sting, unlike the bee, is smooth and does not get stuck in the body of the enemy.

Giant octopus

Living in the Pacific giant octopuses multiply only once in a lifetime. They lay aside up to 400 thousand eggs, and then the female fully devotes herself to caring for the future offspring, even stopping eating. She continuously cares for the eggs, removing the algae adhering to them. The offspring hatch after six months. Newborn octopuses do not exceed the size of rice grains and very few of them manage to survive. The survivors quickly grow to the size of an adult (20-40 kg).

theguardian.com

The female dies shortly after the appearance of the offspring in the light. The male also does not live long – after the fertilization of the female, he swims aimlessly in the ocean, becoming an attractive prey for larger predators.

Lemmings

Despite the ingrained notion of lemmings as suicidal animals, the stories of their mass suicide are more of an amusing legend. Even in the XIX century, scientists drew attention to the sharp fluctuations in the rodent population and suggested that in certain years, when the number of lemmings increases very sharply, the animals follow one another or one of the lemmings – a “conductor” to the abyss or bank of water, where perish.

In fact, lemmings are not herds, flocks or social animals, they move each by themselves and do not follow the leaders.

In 2003, Finnish scientists published a study in which they established: the population of lemmings is regulated by the strict control of their natural predators – ermines, Arctic foxes, snowy owls and gulls.

As for the inclination of lemmings to gather in hordes, it is due to the necessity of migrations with the growth of the population. Although animals move mainly singly, reservoirs form massive accumulations and some of the rodents find themselves in the water. But this does not mean that the whole flock will be completely drowned and the animals that have fallen into the water will drown. They swim well and will be able to escape to the shore, where they will again gather in a flock and continue their migration.

Why do animals kill themselves?

Reports of suicides of animals began to appear a few thousand years ago. So, Aristotle described the stallion, who rushed into the abyss after he mated with his own mother. In the II century BC. e. the Greek scientist Claudius Elian devoted a whole book to this topic, where he described 21 cases of apparent suicidal behavior of animals, including a dolphin that allowed himself to be caught in the net, several dogs who refused food after the death of their owners, and an eagle who “sacrificed himself at the funerary bonfire of his master. ”

Special popularity of the history of suicide animals was acquired in the XIX century. So, in 1845 in the weekly Illustrated London News there was a note about a “healthy, well-groomed and thoroughbred” black dog that allegedly “rushed into the water”, trying to commit suicide. When she was dragged out of the water, she “ran back to the river and tried to drown herself again.”

Later, journalists described another noteworthy case – ostensibly, the deer threw itself into the abyss, so as not to become the prey of the pursuers. There were other similar stories about different animals, from ducks to cats. Nowadays you can hear about dogs who refuse to eat after the death of the owner or about the whales that are thrown ashore.

All these stories are related by one common feature – their authors often attribute to animals “human” motivation, as in the case of a deer allegedly trying to avoid a more terrible death.

In fact, the suicidal behavior of animals is dictated by other reasons. So, after the death of the owner, the dog can refuse food not because he wants to die after the master, but because he was so attached to his master that he can not take food from another person. Whales can perish because they followed a sick member of the pack that had strayed from the course.

“To believe that the animal died of its own free will, as a person dies after the death of a spouse, means simply to project a human approach to it in a romantic spirit,” says the psychiatrist of the Italian University of Cagliari Antonio Preti.

In some species of spiders, females become food for their offspring. This behavior is also difficult to call suicide – rather, it is a way to provide food for the offspring and increase its chances of survival.

However, a consensus on the ability or inability of different species of animals to commit deliberate suicide in the scientific environment is not always present. So, for example, anthropologist Barbara King notes that dolphins are able to hold their breath until they die, so they can die while hunting for them or being in cramped quarters.

“Dolphins breathe consciously and they are very smart, so maybe for them suicide is a matter of choice,” she said.

The same opinion is shared by Dr. David Pena-Guzman from the University of California in San Francisco.

“There is evidence that animals have a life full of emotions,” he notes. “And they have post-traumatic stress disorder, depression and other mental disorders that increase the risk of suicide.”

Back to top button
Close
Close