There is also a higher-end example, there is a kind of liver fluke, its intermediate host is ants, and its final host is cattle or sheep. God, if you were it and came to the ant, would you despair? Because how can you make cattle and sheep learn to eat ants? Well, they are much smarter than you. This parasite enters the ant's esophagus and changes its eating habits-whenever the temperature drops at night, the infected ant will struggle to climb to the top of the grass. What are you doing there? The poor ants waited firmly until the next morning, and it began to go home as if it had recovered. As you may have guessed, when cattle and sheep eat grass, they bring ants into their stomachs-and, of course, triumphant parasites.
Some people put forward a "dominance theory" that parasites can affect the host's nervous system, thus affecting the host's behavior, making the host do things that are more conducive to its own reproduction and increasing its chances of entering the next host. Although there are not many such examples, it is not uncommon. For another example, there is a parasite that can make snakes like to shake. Of course, this is not to practice dancing to please human beings. Insect-eating birds will eat snakes as bugs. There is also a parasite that can make fish jump high from the water and enter the belly of birds. Even the familiar rabies can be seen as such an example. Through the bite between dogs, the virus enters other animals through saliva and spreads.
In this way, many animals end their lives driven by small parasites, just to help parasites enter the next life cycle.
There is a worm called Toxoplasma gondii, which is a single-celled microorganism. Under the microscope, it is very small. As a parasite, it's not good to be too high-profile Toxoplasma gondii has no obvious influence on the host, and at the initial stage of infection, it can cause a mild cold at most. However, Toxoplasma gondii can also cause serious consequences when the host's immune system is not sound enough, such as infants and AIDS patients. It is estimated that nearly 4000 newborns with severe brain diseases are infected with Toxoplasma gondii every year in the United States. It quietly attacks and infects almost all warm-blooded animals that can be touched, from kangaroos in the desert to sparrows flying in the sky. Recently, some researchers have also found this bug in otters, which proves that its tentacles reach into the water.
Toxoplasma gondii is quiet, calm, slow and gentle most of the time, which makes people doubt its spreading ability. Researchers in Sweden have found that Toxoplasma gondii has amazing transmission ability because it can hijack an immune cell called dendritic cells. Once it got on this "mount", it became as excited as Harry Potter got on a broom, rampaging through the host body, ignoring the attack of the immune system. This dendritic cell can help Toxoplasma gondii break through the blood-brain barrier and reach the brain. This strategy enables Toxoplasma gondii to spread all over the body quickly once it enters the body-with this move, it secretly swept the whole warm-blooded animal kingdom.
By purchasing immune cells in the body, Toxoplasma gondii gained some autonomy from its host and lived safely in this "big prison" with a tradition of exclusion. Even in danger, it can penetrate into almost all cells in the body, uncover the cell membrane and have a good sleep.