Ants practically turning into zombies because of a fungus may be one of nature’s most fascinating albeit slightly disturbing mysteries of nature.

In a new study, researchers peel the mystery back a little bit by describing exactly how the fungus gets the victim to do the “death grip.”

Zombie Ants

A fungi that practically turns ants into zombies so that they can spread their spores sounds rather like science fiction, but it is a reality for carpenter ants Camponotus castaneus. Once infected by the fungus Ophiocordyceps unilateralis sensu lato, the victim ant loses its free will and climbs to a higher location where it will grip onto vegetation permanently. There, the victim will be consumed by the fungus from the inside out and eventually dies to spread spores onto the ants below.

Now, in a new study published in the Journal of Experimental Biology, researchers describe exactly how the infamous fungus makes their victims do the death grip with its powerful jaws.

‘Death Grip’

Contrary to what some might believe, the fungus does not actually affect the ants’ brains when it comes to making the victims do the death grip. Once the spore lands on the victim’s exoskeleton, it eats its way inside the creature and forms a network that penetrates its muscles. With the mandibular muscles extensively colonized by the fungus, it breaks open the membrane covering the muscle fibers and then forces it to contract so forcefully that the filaments in them are damaged and swollen.

What’s more, researchers also observed bead structures or vesicles on the fungus filaments, suggesting that they were either the result of the ants’ fighting back from the infection or that they had more lethal toxins that would cause the mandibular muscle to spasm and over-contract, thereby staying in place.

For now, researchers say that there is more to learn about how the fungus affects its host, and the next step is to test the vesicles to see whether they came from the host or from the fungus.