When most people think of fungi, they probably imagine mushrooms growing in the forest or being sold in a grocery store.

The world of fungi is so large and complex that it extends far beyond mushrooms. Take parasitic fungi, for example. Parasitic fungi are a type of fungus that feeds on living organisms, including plants, animals, and other fungi.

Photo: YouTube/Ze Frank

These fungi can have both positive and negative effects on the host, with some fungi, such as cordyceps, actually infecting and controlling their hosts!

Cordyceps gained mass attention thanks to HBO's hit show The Last of Us, which showed what might happen if cordyceps infected human brains.

Photo: YouTube/Ze Frank

While the plot of the show seems dramatic and extreme, it's actually not that far-fetched when you look at what cordyceps can do to flies.

In an entertaining and alarming video, narrator Ze Frank breaks down the realities of several forms of parasitic fungi and how they take over the live bodies of different insects.

Photo: YouTube/Ze Frank

The video was shared as part of Ze Frank's popular YouTube series, True Facts, where Frank narrates the realities of parasitic fungi infecting a fly and controlling its mind and body.

In the end, the parasite kills the fly and feasts on its body, but not before sending out sex hormones to attract other flies to the area.

Photo: YouTube/Ze Frank

It's both fascinating and highly disturbing. Thankfully, Ze Frank has a way of explaining things in a light and humorous tone, making the gruesome reality of the situation much more palatable.

Check out the video below to learn more:

Hopefully parasitic fungi stick with insects and don't adapt to infecting humans anytime soon!