Toxoplasma parasite changes the victim’s behaviour in ways that benefit the parasite. For example, rats infected with the parasite loose their ability to recognise the smell of cat’s urine as potentially dangerous for their lives. On the opposite, the smell starts to attract the rat because it resembles that of a female rat under the influence of the parasite. This attraction exposes the rat to the cat, which kills the rat. Eaten by the cat, the parasite happily continues its life in the intestines of the cat.
Nobody knows how the parasite is able to manipulate the victim’s behaviour.
…another parasite infects freshwater snails and turns them into suicidal zombies. The infected snail develops a bulbous, pulsating eye stalk, and the insatiable urge to climb something tall. That leaves them exposed to predators, and the mutant eye stalk serves as a beacon attracting the attention of hungry birds. Once the snail is eaten, the parasite continues its life cycle in the bird’s intestines.
Did you know that approximately one third of all humans get infected at some point with Toxoplasma, but relatively strong immune system kills it? We are so lucky we don’t turn into suicidal zombies when we get briefly infected with Toxoplasma.
Thanks Emile Dingemans via discovery.com