Have you ever wonder how are parasites capable of manipulating animals or hosts much bigger than them? I used to wonder the same, too. But after studying about it, I realize parasites have a unique and smart system to survive, reproduce by controlling its host.
Parasites are microorganisms that live on or inside a host organism body which they are capable of not only harm but sometimes kill its host as well. Their main survival is through transmitting itself from one host to the other. In order to do so, they need to find their own ways to manipulate their hosts by learning abut the host’s environment, food-cycle and more.
There are many different ways to control their host’s behaviors including
1- Direct Brain Hijacking
(Example 1: Gordian Worm: Imagine its host as cricket which naturally more likely to be in dry areas rather than wet ones. However, the Gordian Worms need water to breed and mate, so when they hit the age to mate, the worms produce a protein that confuses the navigation system of the cricket which results in the confused cricket jumps into a water source. Often times, the crickets will drown and the Gordian Worms can go out to mate. Later on, their eggs will be eaten by water insects which then go out on land and will be eaten by new crickets. This is how the Gordian Worm preserves its species).
(Example 2: Rabies Parasite: These parasites often affect dogs and other mammals, traveling up their host’s nerve systems and into the brain. This results in the inflammation in the dog’s brain which would lead to death, but before they die, the parasites would affect the aggressiveness level inside the brains, increases the virus-transmitting saliva and also making them hard to swallow. All of these effects result in the increased tendency to bite another mammal which makes it easier to pass on the viruses and parasites.
(Example 3: Ophiocordyceps or known as the Zombie Fungus: Their ideal hosts are tropical ants that normally live on treetops. Their first move to the ant is through the piercing exoskeleton which results in the ant’s convulsion that makes them fall off the tree. Then, the parasites would control the ant’s behavior which makes it wander without consciousness until the ant comes across with leaves with the perfect condition for the fungi to breed which allows the fungi to latch itself onto the leave. The ant dies and the parasite will affect its body and build a tall thin stalk on the ant’s neck which after several weeks, shoots out more spored to affect more ants. )
(Example 4: Malaria Parasite: This parasite is an extremely dangerous kind for humans which is responsible for hundreds of millions of malaria cases every year The parasite’s hosts are mosquitos which are the spreading agents of the virus that causes malaria. The infected mosquitos tend to bite more frequently and longer. Humans who got the viruses are more attracted to mosquito bites. )
From the parasites that affect the directly to the brain (Gordian Worms), to the ones that blocks the host’s enzyme system to make them go to more preys to infect (Malaria Parasites), the ones that overdrive the immune system and increase the anxiety rates (Rabies Parasites), these parasites have powerful and effective way to manipulate species who are much bigger then them. It’s scary when the parasites can be so manipulative because we do not know what are the actions that they made us do and how much are we actually being controlled by them?