Buzz
Reliable reports suggest that the zombie apocalypse is imminent. Yet, as with many phenomena, Mother Nature is already outpacing us, especially when it comes to zombies. We've previously discussed strange instances of mind control among animals and insects, but nature’s ability to evoke pure terror is unmatched. Below are 10 more examples of insect zombies and the chilling ways parasites manipulate their hosts' minds and lives.
10. Amber Snails
Parasite: Leucochloridium paradoxum
Snails might not lead the most glamorous lives, but they make do with what they have. Their shells provide protection, they are hardwired to stay away from sunlight and open spaces where predators could be waiting, and their slimy coating makes them unappealing to most animals. However, when amber snails fall prey to the zombie-like influence of the Leucochloridium paradoxum flatworm, their existence becomes one of the most agonizing in the invertebrate world.
Commonly known as the green-banded broodsac, this parasite spends its adult life within bird intestines, laying eggs that eventually make their way into bird droppings. If a snail happens to ingest the droppings, the nightmare begins. The eggs hatch into miracidia, or larvae, that travel through the snail's digestive tract, developing into sporocysts—swollen tubes that transform the snail’s eyestalks into broodsacs, where flatworm juveniles are pumped into the empty space.
At this stage, the snail is completely blind and loses its instinctual fear of sunlight—exactly what the flatworm needs to complete its lifecycle. The broodsacs in the eyestalks begin to twitch and pulsate when exposed to sunlight, mimicking the movement of a caterpillar, which attracts birds. If the snail is lucky, a bird will eat it whole; otherwise, the bird may simply tear off the eyestalk. Eventually, the stalk regenerates, and the cycle repeats until the snail meets its demise.
9. Giant Gliding Ants
Parasite: Myrmeconema neotropicum
Giant gliding ants are found in the rainforest canopy of Central America, building their nests high in the treetops, sometimes as high as 130 feet (40 m) above the forest floor. Since ants that fall to the ground are unlikely to make it back to their colony, they have evolved a fascinating ability—they can glide, like flying squirrels, back to the tree trunks.
In 2005, during a trip to Panama to investigate this unique behavior, scientists made another startling discovery—some of the ants’ gasters (rear ends), which are typically black, turned bright red, and the ant would raise its gaster into the air. After dissecting one of these ants, they found its gaster was filled with parasitic nematode eggs, which were doing a number of things to the ant.
The chemical produced by the nematode eggs causes the ant to stop producing pheromones and forces it into a slow, unsteady walk with its gaster held high. Additionally, the exoskeleton around the gaster thins, allowing the bright red eggs to show through, giving the ant a striking appearance—one that resembles berries commonly eaten by birds in the region. This combination makes the ant appear like a sitting target for a bird. Once consumed, the nematode infects the bird, lays more eggs, and the cycle continues when the eggs are passed in the bird's feces, eventually reaching another ant colony.
8. Pill Bugs
Parasite: Acanthocephala
Parasites that manipulate their hosts' behavior usually have one of two goals: either to protect the host, or to make it more susceptible so that the parasite can complete its life cycle in another species. Acanthocephala worms follow the latter strategy, transforming various species—particularly pill bugs—into mindless vessels that unwittingly carry them to their true hosts, European starlings.
Pill bugs typically favor dark, damp environments. If you lift a log in the summer, you’ll likely spot several of these tiny creatures scurrying away from the light. However, pill bugs infected with acanthocephala behave completely differently—they become phototactic, meaning they are drawn to light, even though venturing into open spaces spells certain doom. Even more disturbingly, the parasite also causes the pill bugs to favor lighter surfaces, making them easier for starlings to spot from above. The parasite overrides all of the pill bugs’ defense mechanisms, luring them into perilous situations.
Somewhat unrelated, after two adult acanthocephala worms mate (while residing in a bird), the male produces a cement-like substance that seals the female’s vagina, preventing her from mating with any other worms.
7. Grasshoppers and Ants
Parasite: Strepsiptera Myrmecolacidae
Strepsiptera insects may not be the most cruel parasites on this list, but they certainly rank among the oddest. With 600 species of these tiny flies, each species targets its own preferred host. For one group, the Myrmecolacidae, it's not enough to have just one host—females reside in grasshoppers or crickets, while males live in ants.
Let’s talk about females first: When a female Strepsiptera finds a suitable grasshopper, she attaches herself and starts secreting enzymes that burn a hole through the grasshopper's abdomen. Then, she climbs inside and releases another enzyme that alters the grasshopper's mtDNA, forcing the host to generate a sac from its own tissue to protect the parasite from antibodies. Throughout this entire process, the female remains with her head protruding from the grasshopper’s abdomen, emitting pheromones to attract a male. Meanwhile, the grasshopper goes about its business, oblivious to the fact that 90% of its abdomen is now occupied by something entirely foreign.
Male Myrmecolacidae larvae, conversely, live within ants. Infected ants abandon their colonies and wander aimlessly while the larvae grow. When the larvae are fully developed, they drive the ant to the top of a blade of grass, where the larvae emerge as winged adults. These adults then fly off in search of a mate. The strangest aspect of these flies (as if the rest of their lifecycle isn’t odd enough) is that they possess mouths, but their mouthparts are nonfunctional—males never eat. They live for about two hours, just long enough to mate before dying.
6. Carpenter Ants
Parasite: Ophiocordyceps unilateralis
We discussed this particular ant in the first article (linked in the intro), but recent studies have uncovered an even greater degree of specialization in the ophiocordyceps fungus that affects it, so it’s worth revisiting. Interestingly, this phenomenon doesn’t occur in just one species of ant—at least four different species of carpenter ants are affected by this process, likely even more. What makes it so intriguing is that each species of ant has its own distinct species of fungus that targets it, even though all the ants coexist in the same environment.
It’s no surprise that scientists have long been fascinated by the relationship between ants and the parasitic fungus. The fungus spores infect an ant, compelling it to climb a tree, bite down on a leaf, and ultimately die. A few days after death, a mushroom emerges from the back of the ant’s head, positioned perfectly to release more spores that fall to the forest floor.
It gets even more bizarre, because healthy ants have evolved to recognize when one of their own is infected. In 2009, researchers in Thailand found that zombie ants consistently traveled to specific locations to die, which they called 'graveyards.' The team discovered dozens of dead ants clustered in these spots, and interestingly, out of the 2,243 ant carcasses they found, only two live ants were anywhere near these graveyards, suggesting that healthy ants deliberately avoid these areas.
5. Honey Bees
Parasite: Apocephalus borealis
In 2006, a strange phenomenon began to occur: bees started disappearing. This event, now known as colony collapse disorder, has led to the death or mysterious disappearance of millions of bees. After years of uncertainty, scientists now believe they have identified the cause: deadly, mind-controlling parasites.
The first signs of the parasites were observed in 2012 across Northern California and Washington state. The culprit: Apocephalus borealis, or phorid flies. The fly lands on a bee and injects its eggs into the bee’s abdomen. Once the eggs hatch, the bee starts acting erratically, flying in disorganized circles and stumbling as it attempts to walk. These 'zombees' then leave their hives at night, fly a short distance, and crash to the ground. A week later, several larvae will emerge from the bee's body.
4. Bumblebees
Parasite: Conopidae larvae
It turns out that bees are quite the ideal hosts for malicious insect puppet masters. Conopid flies, found in Canada and Europe, prey on various insects, particularly bumblebees. These flies are brutal—not only do they consume the bee from the inside out, but they also force the bee to dig its own grave first.
The process begins when a conopid fly lands on a bumblebee and quickly injects it with an egg shaped like a harpoon. As the larva hatches, it feeds on the bee’s innards, causing the bee to act more and more erratically as its organs are consumed. After 10 days of this torment, the larva forces the bumblebee to the ground, where it instinctively tries to bury itself. This behavior is likely an attempt to protect the larva, which will remain inside the empty shell of the bee as it pupates before emerging as an adult fly.
3. Ladybugs
Parasite: Dinocampus coccinellae
Ladybugs (also known as ladybirds outside the US) are easily recognizable by their bright red shells and black spots. These vivid colors serve as a warning to predators that the ladybug is likely toxic or at least not very appetizing. This is exactly why the Dinocampus coccinellae wasps choose ladybugs to protect their offspring.
When an adult wasp locates a suitable ladybug, it lands, bends its stinger underneath the beetle, and deposits a single egg into the ladybug’s abdomen. After about five days, the wasp larva hatches and consumes any ladybug larvae already present inside the host. The larva then attaches to the ladybug like a life-support system, drawing nutrients directly from its body while the ladybug continues to move and eat.
The wasp larva will live inside the ladybug for up to a month, but after a certain period, it severs the nerves controlling the ladybug’s legs, paralyzing it. It then burrows out through the ladybug’s abdomen and forms a cocoon between its legs. Surprisingly, it does not kill the ladybug immediately because it still requires protection. Instead, it manipulates the ladybug into remaining still, twitching slightly to give the impression of life. After 6-9 days, the fully matured wasp emerges. If the ladybug has survived the nearly 40 days of control, it is free to leave.
2. Corn Earworm Moths
Parasite: Hz-2v virus
On the lighter side of viral mind control, the Hz-2v virus does something peculiar to Helicoverpa zea moths, commonly referred to as corn earworms—it compels them to mate incessantly. Since the virus is sexually transmitted, it relies on hosts that reproduce quickly for its spread. However, it doesn't just leave things to nature—it interferes with the female moth's pheromone-producing centers, causing them to release up to seven times more pheromones than typical moths. In the animal kingdom, pheromones equate to sexual attraction, and in a 2005 study, females infected with the virus would immediately call for a mate after finishing with another male, effectively doubling the number of potential partners they encountered.
1. Gypsy Moth Caterpillar Virus
Parasite: Baculovirus
Parasites use a variety of sinister methods to manipulate their hosts, but none are as downright cruel as causing the host to disintegrate into a sticky, gooey mess. For a parasite, that’s a harsh move. Perhaps that’s why the gypsy moth caterpillar’s greatest threat isn’t a parasite—it’s a virus. The baculovirus targets invertebrates like caterpillars and, with the help of a gene called EGT, takes control of the host’s brain, compelling it to climb to the treetops.
Once at the top of the tree, the caterpillar pauses, while the virus works its sinister magic inside. It begins converting the caterpillar's body into more virus material. The result? The once lively caterpillar slowly dissolves, its body literally melting away as it sits. The liquefied remains then drip onto the tree’s leaves, which will be consumed by other caterpillars soon after.
