Nature is filled with fascinating things. However, there are plenty of times when those things aren’t weird and wonderful so much as straight-up nightmarish. For an excellent example, look no further than how parasites are capable of changing their hosts’ behavior, so much so that it wouldn’t be an exaggeration to call some examples mind control.
Those who are skeptical should consider the case of the zombie ant fungus. In short, the spores of the fungus infect unsuspecting ants that are foraging on the rainforest floor, where they will develop for 3 to 9 days before getting ready to move on to the next stage of their life cycle. Once they are ready, they will control the ant so that it will climb a tree to around 25 cm off of the ground, choose a location with sufficient humidity for the fungus to flourish, clamp onto a leaf using its mandibles, and then die. In time, a fungal stalk will emerge from the ant’s corpse, from where it will be able to rain more spores on unsuspecting ants.
Unfortunately for those who are squeamish, the zombie ant fungus is far from being unique. For example, the kamikaze horsehair worm starts out in the water. There, its larva form will be consumed by the larva of an insect such as a fly or a mosquito, which in turn, will be consumed by a cricket or a grasshopper. Once ensconced in its new host, the kamikaze horsehair worm will start growing and growing until it is ready to reproduce, which is when it will cause its host to jump into the water. This is lethal for the host because it can’t swim, but the water will be just fine for the kamikaze horsehair worm when it heads out to reproduce. In some cases, the hosts can be unfortunate enough to have more than one parasite, with one researcher stating that they had witnessed one case in which no fewer than 32 such parasites squirmed out of the same host.
With that said, the kamikaze horsehair worm isn’t even the most impressive example of control exerted by parasites, as shown by the castrator barnacle. In short, the castrator barnacle enters crabs by slipping through the chinks in their claw joints. Once they have managed to make it in, the parasite will start using the crab’s nutrients to produce millions and millions of barnacle larvae. In the case of female crabs, the castrator crab will cause it to start caring for the larvae as though they were her own. Meanwhile, in the case of male crabs, they will be feminized to make them more suitable for the same purpose, with results that range from the shrinking of their gonads to the enlargening of their abdomens to make them better at carrying the barnacle larvae. Based on this, it should be obvious where the name of the parasite comes from.
Is Toxoplasmosis Changing Your Behavior?
It is natural for people who have heard about these parasites to wonder about whether there are any parasites out there that can affect humans in the same manner or not. Unfortunately, there is reason to believe that toxoplasmosis found in cats and other places can have an impact on human behavior. However, the impact don’t seem to be anywhere near as serious as the aforementioned examples, which should come as welcome news for worried individuals.
For those who are curious, toxoplasmosis has been known to cause infected rats and mice to lose their fear of cats, which is necessary because it reproduces in cats. In humans, there is some evidence to suggest a correlation between infection in humans and increased risk-taking in humans. However, it is important to note a couple of things. First, the correlation isn’t as strong as people might fear, with an expert stating that it isn’t enough to make an introvert into an extrovert. Second, correlation is not necessarily the same as causation. Simply put, we don’t actually know whether the toxoplasmosis is causing the increased risk-taking or not because there are other potential explanations as well. On top of this, toxoplasmosis is more common in schizophrenics than in the rest of the population, but since schizophrenia is so complicated, it can’t be identified as a cause so much as one of a number of potential risk factors at this point in time.
Due to this, there is no need for people to get rid of their cats or take other kinds of drastic action. This is particularly true because people are likelier to get toxoplasmosis from either uncooked meat or unwashed vegetables than their cats, which might not even carry the parasite if they live indoors. Instead, they should read up on the issue, which should enable them to prevent infection while still remaining as a happy cat owner.