Our experts weigh in on the real ghouls haunting our neighborhoods on Halloween
Image Credit: Kevin Decherf from France, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons
It’s that time of year again, when kids and adults alike don their most ghoulish garb hoping to scare up a few screams. So, we thought we’d offer up a few creepy characters of our own to tingle the hairs on the back of your neck. You won’t find their likenesses in the costume shops, though, because we’ve recruited AGNR experts to help us dig up the real-life monsters haunting your own backyard!
Nature’s Zombies
You may have heard of Zombie ants, those powerless creatures whose brains are infected with a fungus that forces them to climb to the top of a leaf and swing in the wind so the fungus can spread its spores to the next victim. According to entomology professor and fungi expert Ray St. Leger, these zombie ants are found primarily in tropical environments, so there’s not much chance of seeing one here in the DMV, but there is a pathogen with similar mind-control powers altering the behavior of mice all over our region.
The parasite Toxoplasma gondii causes major changes to the brains of mice that make them bolder and less anxious around predators. Infection with the parasite leads mice to scurry perilously close to prowling cats and rats. In fact, pet cats that are allowed to wander outside can pick up the parasite by hunting infected mice.
And an infected pet cat can transmit the parasite to humans. Although very few people come down with symptoms, infection can cause neurological and even psychological problems, and it can be deadly to unborn children. That’s one reason why people should keep their cats inside according to a research paper by Environmental Science and Technology graduate student Daniel Herrera.
True Vampires
Vampires of legend possess a host of bat-like qualities and behaviors, like sporting black, wing-like capes and hanging upside down to sleep in dark corners. But real bats almost never mirror vampire-like traits. As Shannon Browne, a senior lecturer in the Department of Environmental Science and Technology explains in Bat Myths Busted, only 3 of the world’s 1,400 bat species survive by drinking animal blood, and those are not found in Maryland.
But that doesn’t mean there aren’t real blood suckers to worry about. Nature’s real Vampires, ticks, don’t kill by draining victims, they kill by passing diseases. The most worrisome ones around here are black-legged ticks, which carry a plethora of diseases that can infect humans, pets and livestock. They’re also known to live on every continent but Antarctica, and according to Professor of Veterinary Medicine Utpal Pal’s recent article in Science Translational Medicine, the threat from these miniscule vampires is a “ticking” time bomb. With climate change increasing their geographic ranges, Pal said it’s urgent for governments and researchers to focus resources on developing vaccines against the pathogens ticks carry—diseases like Lyme’s, Anaplasmosis, Babesiosis, Rickettsiosis and Tularemia.
If that’s not enough to earn them some respect as fascinatingly ghoulish, consider this: black legged ticks have evolved to recognize immune molecules from infected host blood, so they know before an infection ever has a chance to start, if they’ve taken a meal from a host with Lyme’s disease. They respond by producing an antibiotic protein in their blood and by growing more rapidly so they have a chance to reproduce (and pass along the disease) before they can succumb to the disease.
Poisonous Creepy Crawlies
Sand worms, giant, flesh-hungry worms that move at lightning speed across deserts and through city streets have inspired fear and awe in movie goers for decades, from Beetlejuice and Tremors to the quintessential Dune. But here’s a twist that the creators of those creepy crawlies never conjured: poisonous skin.
But Mother Nature did think of that, and she gave it to a slithering foot-long worm that has been invading local backyards. Even more creepy, if you chop it up, the pieces will grow into new worms, multiplying the horror.
UMD entomologist Mike Raupp says these hammerhead worms, named for their distinctive shape, secrete the same neurotoxin puffer fish use to paralyze potential predators. Although handling them can cause skin irritation, they’re not a real threat to most people, but curious pets that eat them could be in danger.
What’s more, hammerhead worms are voracious eaters that hunt the slimy creatures that currently live here and play important roles in the ecosystem, like earthworms, slugs and snails.
Deer Ghosts
Maybe not ghostly in the traditional sense, but white-tailed deer are everywhere, even when you can’t see them. That’s what Environmental Science and Technology Associate Professor Jennifer Mullinax found in a study of deer movements through parks and neighborhoods of Howard County, MD.
She found that deer in suburban environments often bed down and spend the night within 150 feet of residential properties, and people don’t even know they’re there. For Mullinax, that has implications for controlling the ticks deer carry and the Lyme’s disease they help to spread. But for the average suburbanite, it may just solve the problem of who has been trimming the landscaping every night while they sleep.
