Blog post Tara Roth, Ph.D.

Zombies, Vampires, Werewolves, and Other Tiny Monsters

We’re not trying to scare you, but…all the movie monsters of your nightmares are real. They’re just a little smaller than you expected.


You awake from a restless sleep, climb from your bed and wander to the kitchen. A flick of the light switch and there, on the floor, a small body lies before you. It lays on its back. Silent, still, dead. You reach to pick it up when suddenly the legs begin to twitch. The cockroach is alive! While cockroaches have a small brain, they can continue to run around without it. Scientists have removed the heads from cockroaches and the insects lived for about a week before they finally died of starvation. Cockroaches are also capable of coming back to life after being drowned for 15-30 minutes making them real life zombies – sort of.

Real Body Snatchers

These creatures are native to the planet earth but no less deadly. The hairworm (Paragordius tricuspidatus) infects crickets and takes over their bodies. The worm slowly grows inside the cricket, feasting and filling the entire body until it reaches adulthood. Once the worm has grown to its full length (up to 6 inches!) it seizes control of the cricket’s brain and makes it jump into the nearest pool of water, then emerges from its body in a long thin thread to swim away while the cricket drowns.


It may not turn into a wolf under the full moon but no transformation is required for this murderous mouse. The scorpion mouse (Onychomys spp.) is fully carnivorous and feeds on insects, scorpions, snakes and even other mice. It defends its territory by howling like a small wolf and attacking viciously. This small terror frequently kills and eats venomous arthropods like scorpions and centipedes, cracking through their hard exoskeletons and cutting off their nervous system until the prey lies paralyzed.


You’d think the mosquito would be an easy choice for this category but unlike the vampire of legend, mosquitoes fuel their powers of flight with sugar water or nectar and use blood only to lay eggs. To be a REAL vampire, one must survive only on blood. I present to you, the bat fly. Bat flies (Nycteribiidae) are flattened, spiderlike, nightmare monsters without eyes that almost never leave the body of the bat. Both males and females feed on the blood of their hosts and they can be very prevalent in caves where bats roost in high numbers.

‘The Blob’

Dubbed “The T.rex of the Dinoflagellate World”, predatory algae (Pfiesteria spp) do not make their own food like most algal species and instead consume the flesh of other aquatic organisms. During large algal blooms, certain species of killer algae will release toxins that paralyze the respiratory tract of fish, causing them to die of suffocation. The Pfiesteria then shifts to an amoeboid form, settles to the bottom where the carcasses lie, and feeds on the tissue of its once-living prey.


You wouldn’t think a moth could be a monster of legend but the predatory bagworm (Perisceptis carnivora) begs to differ. Bagworm caterpillars are unique in that they wrap themselves in a cocoon of fine threads that both help protect them from the elements and allow a sticky surface to attach pine needles, bits of leaves and other bits of disguise. Instead of pine needles, the predatory bagworm adorns its fine muslin with the body parts of its prey then lies in wait until a foolhardy insect dares to disturb its slumber.


Much like the chest-bursting Alien, parasitoid wasps lay their eggs inside the body of other insects. There, the larvae feast on the soft tissue, allowing the prey to live – for a while. Once the larvae have completed their maturation and are ready to become adults they burst forth out of the insect’s body in a gory mess before turning into their final form – a wasp ready to kill again.


Oh, spiders. You’re so misunderstood. While there are several species of spider that are poisonous (the black widow for example) most are harmless and are actually very important for controlling pests in and around our homes. Many of the species that are capable of giving a painful bite (like the wolf spider) are completely solitary and will only bite if threatened. Seeing wolf spiders in and around your homes is very seasonal and only typically occurs in the fall when the males leave their burrows looking for mates.


Another misunderstood species, bats may look creepy with their leathery wings but they are actually really beneficial! Most bats (about 70% of all species!) eat insects which is good news for us humans. In fact, there are only three species of vampire bat that feed on blood and all live in Central and South America. Bats greatly range in size with the smallest, the bumblebee bat, at a little over an inch in length and the largest, the golden-crowned flying fox, at 13 and a half inches in length. All of the largest bats feed on fruit and live in tropical regions. Unfortunately, bats are reservoirs for many serious diseases including rabies so while they’re wonderful to have around, it’s not a good idea to allow them to live inside your home.