[1] It implies a wide range of higher cognitive capacities that experts have been wary to ascribe to nonhuman animals such as a concept of self, death, and future intention.
[8] Some animals, such as octopuses, stop eating food and waste away after reproducing, seemingly losing any desire to live.
[13] In 1845, the Illustrated London News reported that a Newfoundland dog had been acting less lively over a period of days before being seen "to throw himself in the water and endeavor to sink by preserving perfect stillness of the legs and feet".
[14] The newspaper ran stories on other dogs, as well as ducks, that had also allegedly drowned themselves, although the veracity or certainty of these cases is disputed.
Aristotle described an unverified story involving one of the King of Scythia's horses dying by suicide after having been made to unwittingly impregnate its mother in his History of Animals.
[6] Carpenter ants and some species of termite will rupture glands and expel a sticky toxic substance thought to be an aliphatic compound in a process called autothysis.
Termites will use autothysis to defend their colony, as the ruptured gland produces a sticky harmful secretion that leads to a tar baby effect in defense.
[24] Honeybees use their stinger to deliver poisonous chemicals to their attacker, effectively both injuring the predator and killing the insect in the colony's defense.
[30] Infection with Toxoplasma gondii has been shown to alter the behavior of mice and rats in ways thought to increase the rodents’ chances of being preyed upon by cats.
However, infected clams are concentrated in the higher parts of the tidal flats, closer to shore, and leave conspicuous zig-zag markings in the sand.
Visual and tactile cues have shown to be used by oyster catchers and other shore birds, the definitive hosts of the parasite.
This misconception was first popularized by media in the 1960s, such as a mention in the Cyril M. Kornbluth short story "The Marching Morons" in 1951 and the 1955 comic "The Lemming with the Locket", inspired by a 1953 American Mercury article.
[41][42] Perhaps one of the most influential factors in this misconception was the 1958 Academy Award-winning Disney film White Wilderness, which showed staged footage of lemmings jumping off a cliff during reproduction.
[43] Werner Herzog's 2007 Academy Award-nominated documentary film Encounters at the End of the World features footage of a penguin marching away from the sea, going inland to its certain death.