reclinervellus nielseni
A larva of Reclinervellus nielseni parasitizing Cyclosa argenteoalba in Japan. Image courtesy of Polysphinctine (Own work) [CC BY-SA 4.0], via Wikimedia Commons

Nature’s Freakiest Horror Stories

Zombie ants, parasitic wasps, sentient fish tongues... this Halloween, look no further than the natural world for your spooky needs.


This Halloween, many people will turn out the lights and enjoy the thrill of a scary movie. From zombies, to slithering worms, to creepy long-haired girls that come through your TV, humans have thought up nearly every possible scenario to horrify and disgust each other.

But nothing compares to these shudder-inducing true stories from Mother Nature.

Dawn of the Dead Ants

Imagine a carpenter ant walking in a tropical forest, foraging for food along its usual route when, all of a sudden, it feels an odd sensation. It begins to act erratically and has the sudden urge to leave its usual path and climb upwards. It meanders out onto the underside of a leaf and clamps onto the leaf with its mouth, unable to let go.

There it will stay until the fungus with which it’s infected kills it and grows a spore-releasing stalk that bursts out of its head.

ophiocordyceps unilateralis
Dead ant biting the underside of a leaf as a result of infection by O. unilateralis. A fungal stalk emerges from the back of the ant’s head. The photograph has been rotated 180 degrees to aid visualization. Image courtery of David P. Hughes, Maj-Britt Pontoppidan [CC BY 2.5], via Wikimedia Commons
Spores of the “zombie ant fungus”, Ophiocordyceps, are abundant in the forests of Thailand and Brazil, infecting ants and releasing chemicals that hijack the ant’s nervous system. The ant then becomes a helpless carrier, bringing the fungus to its preferred destination.

And infected ants can’t expect any help from their buddies. If the ant colony realizes an ant is infected, they quickly carry it away and dump it as far from the colony as possible.

Rosemary’s Baby Wasp

Imagine a spider sitting in its web minding its own business, when suddenly, a wasp attacks. Thankfully, after a brief struggle, the wasp flies away and the spider relaxes again. Little does it know, it’s just been given the worst babysitting gig of its life.

The wasp, Reclinervellus nielseni, left the spider alive to take care of the egg it just deposited onto the spider’s back.

As the egg develops into a larva, it instructs the spider to build a protective web, almost three times stronger than the spider’s usual web. Once complete, the larvae feeds on the paralyzed spider, eventually discarding its body, and uses the web as a safe haven to build its cocoon and complete its metamorphosis.

Finding Nemo’s Tongue

Cymothoa exigua
Cymothoa exigua, the tongue-eating louse, inside the mouth of a Sand steenbras. Image courtesy of Marco Vinci (Own work) [CC BY-SA 3.0], via Wikimedia Commons
Imagine a fish swimming along the California coast, enjoying the swell of the waves. But in that water, lurks Cymothoa exigua, a slimy little louse that infiltrates the fish’s mouth through its gills. Once there, the louse feeds on the blood from the fish’s tongue until the tongue atrophies and falls off. But that’s not all. The louse then attaches itself to the tongue stub, acting as the fish’s tongue. The fish stays alive.

Apart from having your tongue eaten out, that’s not so bad, right?

Maybe going outside and looking around is the scariest thing you can do this Halloween!

‹ Previous post
Next post ›

Malgosia Pakulska is a freelance science writer, speaker, and blogger. She completed her PhD in Professor Molly Shoichet’s lab studying drug delivery systems for spinal cord regeneration after injury. She is still passionate about research and wants to share that excitement with the public. When she is not in the lab, she is experimenting in the kitchen and blogging about it at Smart Cookie Bakes.