Parasites are capable of doing some pretty incredible things to their host’s behavior. You might have read recently that there's a link between the Toxoplasma gondii parasite, often transmitted to humans via cats, and the decision to follow a career in business.
If you thought that was wild, you should hear about the Massospora fungus and its despicable behavior towards the cicada.
New Scientist has come across a particularly fascinating research paper on the pre-print server bioRxiv that explains how this parasitic fungus sends cicadas into a mad sex orgy, including male-on-male action, by getting them high on drugs. In turn, this rampant romping increases physical contact between individuals and helps the parasite spread to new hosts. Devilishly genius.
The drugs of choice are cathinone, an amphetamine, and psilocybin, the well-known psychoactive chemical found in magic mushrooms. The researchers found traces of these chemicals in the “plug” of the cicada. This is a white growth that sprouts on the abdomen of the insect after it becomes infected by the fungal spores.
However, it’s not all fun and games for the cicada. This plug can often cause the insect's abdomen and genitalia to snap off during sexual intercourse, thereby making it infertile. Nevertheless, the insects remain undeterred and still try to go at it, fueled by their intoxication, causing even more damage and ultimately death.

The researchers concluded their review of this bizarre sex-mad chain of life by explaining that this relationship could actually hold some real-world benefits for humans.
“We anticipate these discoveries will foster a renewed interest in early diverging fungi and their pharmacologically important secondary metabolites, which may serve as the next frontier for novel drug discovery and pave the way for a systems biology approach for obligate fungal pathogens spanning the known diversity of Kingdom Fungi,” the study authors write.
While we’re on the subject of mind-controlling parasites, a burgeoning field called neuro-parasitology, you’ll no doubt be interested to hear how the fungi Cordyceps invade ants' brains, essentially turning them into zombies. Scientists have known about this toxic relationship for some time, however, just recently they have worked out the highly specific mechanisms through which this takes place. You can find out more about that right here.