'Zombie' Ants And The Fungus That Saves Them

As you can probably tell, at least one person on this blog's masthead likes ants.

So we've always been bummed that we haven't had the opportunity to tell you about zombie ants, but today we are glad to report there is a new development in the field. Luckily, it's a good-news report about a fungus that limits the fungus that turns ants into zombies.

In the current edition of the journal PLoS ONE, an international research team led by David Hughes of Penn State University reports that they've found the fungus that allows an ant colony to survive infestations by a "zombie-ant fungus, which invades an ant's brain and causes it to march to its death at a mass grave near the ant colony, where the fungus spores erupt out of the ant's head."

"In a case where biology is stranger than fiction, the parasite of the zombie-ant fungus is itself a fungus — a hyperparasitic fungus that specializes in attacking the parasite that turns the ants into zombies," Hughes said in a university press release.

So let's back up a bit and give you two gross (we warned you) visuals. Here's an ant infected with Ophiocordyceps unilateralis s.l. That's the stalk of the fungus sticking out of its head and controlling its body movements in order to move it to an ideal area where it can spread to other ants:

Enlarge this image toggle caption David Hughes/Penn State University David Hughes/Penn State University

Scientists first reported the "zombie fungus" back in March of 2011. Now scientists have found the thing that likely saves the ant zombies. Or rather, a fungus that essentially castrates the zombie fungus, making only 6.5 percent of spores viable. One more gross picture — this one of an ant that was infected by the zombie fungus and then infected by the anti-zombie-fungus fungus:

Enlarge this image toggle caption David Hughes/Penn State University David Hughes/Penn State University

"Even though there are a lot of dead and infected zombie ants in the neighborhood, only a few of the spores of the zombie-ant fungus will become mature and able to infect healthy ants," Hughes said. "Our research indicates that the danger to the ant colony is much smaller than the high density of zombie-ant cadavers in the graveyard might suggest."

With that, we'd like to remind you that the official NPR AntCam is still going strong. We can say with pretty good certainty that none of our ants are zombies. And we can also report that the ants have been working hard trying to escape from their blue environment: