10 Juicy Facts About Leeches

Ian Cook
Ian Cook

Leeches get a bad rap, but they’re actually pretty cool once you get to know them—and we're finding out more about them, even today. Recently, a team led by Anna Phillips, curator of parasitic worms at the Smithsonian National Museum of Natural History, discovered a new species of medicinal leech (pictured above) in a Maryland swamp. We asked parasite expert and curator at the American Museum of Natural History Mark E. Siddall to share some surprising facts about the worms we love to hate. 

1. Not all leeches suck blood.

Hematophagous, or blood-feeding, species are only one type of leech. “The vast majority of species are [hematophagous],” Siddall tells Mental Floss, “but it depends on the environment. In North America, there are probably more freshwater leeches that don’t feed on blood than there are blood-feeders.” And even among the hematophagous species, there are not too many who are after you. “Very few of them are interested in feeding on human blood,” Siddall says. “Certainly they’ll do it, if they’re given the opportunity, but they’re not what they’re spending most of their time feeding on.” 

2. Leeches are everywhere.

Japanese leech on a log
Pieria, Wikimedia Commons // Public Domain

“Every continent on the planet has leeches, with the exception of Antarctica,” Siddall says. “And even then there are marine leeches in Antarctic waters.” Humans have co-existed with leeches for so long, according to Siddall, that just about every language has a word for leech. 

3. Leeches have made a comeback in medicine.

Bloodletting for bloodletting’s sake has fallen out of favor with Western physicians, but that doesn’t mean medicinal leeches are enjoying a cushy retirement. Today, surgeons keep them on hand in the operating room and use them as mini-vacuums to clean up blood. “That is a perfectly sensible use of leeches,” Siddall says. Other uses, though, are less sensible: “The more naturopathic application of leeches in order to get rid of bad blood or to cure, I don’t know, whatever happens to ail you, is complete hooey,” he says. How on Earth would leeches take away bad blood and leave good blood? It’s silly.” 

4. Novelist Amy Tan has her own species of leeches.

Land-based leeches made an appearance in Tan’s 2005 book Saving Fish from Drowning, a fact that instantly put the author in leech researchers’ good graces. “There are not a lot of novels out there with terrestrial leeches in them,” Siddall says. So when he and his colleagues identified a new species of tiny terrestrial leeches, they gave the leech Tan’s name. The author loved it. “I am thrilled to be immortalized as Chtonobdella tanae,” Tan said in a press statement. “I am now planning my trip to Queensland, Australia, where I hope to take leisurely walks through the jungle, accompanied by a dozen or so of my namesake feeding on my ankles.”

5. Leeches can get pretty big.

The giant Amazon leech (Haementeria ghilianii) can grow up to 18 inches and live up to 20 years. And yes, this one’s a blood-feeder. Like all hematophagous species, H. ghilianii sticks its proboscis (which can be up to 6 inches long) into a host, drinks its fill, and falls off. Scientists thought the species was extinct until a zoologist found two specimens in the 1970s, one of whom he named Grandma Moses. We are not making this up.

6. Leeches make good bait.

Many walleye anglers swear by leeches. “A leech on any presentation moves more than other types of live bait," pro fisher Jerry Hein told Fishing League Worldwide. "I grew up fishing them, and I think they're the most effective live bait around no matter where you go." There’s an entire leech industry to provide fishers with their bait. One year, weather conditions kept the leeches from showing up in their typical habitats, which prevented their collection and sale. Speaking to CBS news, one tackle shop owner called the absence of leeches “the worst nightmare in the bait industry.”

7. Leech scientists use themselves as bait.

Siddall and his colleagues collect and study wild leeches. That means hours of trekking through leech territory, looking for specimens. “Whether we’re wandering in water or traipsing through a bamboo forest,” Siddall says, “we are relying on the fact that leeches are attracted to us.” Do the leeches feed on them? “Oh my god, yes. We try to get them before they feed on us … but sometimes, obviously, you can’t help it.”

8. Leech sex is mesmerizing.

Like many worms, leeches are all hermaphroditic. The specifics of mating vary by species, but most twine themselves together and trade sperm packets. (The two leeches in the video above are both named Norbert.)

9. Some leech species make surprisingly caring parents. 

“There’s a whole family of leeches that, when they lay their eggs, will cover them with their own bodies,” Siddall says. “They’ll lay the eggs, cover them with their bodies, and fan the eggs to prevent fungus or bacteria from getting on them, and then when the eggs hatch, they will attach to the parent. They’re not feeding on the parent, just hanging on, and then when the parent leech goes to its next blood meal it’s carrying its offspring to its next blood meal. That’s pretty profound parental care, especially for invertebrates.”

10. You might be the next to discover a new leech species. 

Despite living side-by-side with leeches for thousands of years, we’ve still got a lot to learn about them. Scientists are aware of about 700 different species, but they know there are many more out there. “I’ll tell you what I wish for,” Siddall says. “If you ever get fed on by a leech, rather than tearing off and burning it and throwing it in the trash, maybe observe it and see if you can see any color patterns. Understand that there’s a real possibility that it could be a new species. So watch them, let them finish. They’re not gonna take much blood. And who knows? It could be scientifically useful.”

How to Keep a Cat Out of Your Christmas Tree

MW47/iStock via Getty Images
MW47/iStock via Getty Images

You may be able to resist poking around the Christmas tree until December 25, but your cat has different plans. The tree you spent hours decorating is nothing more than an oversized toy to the feline in your home. Fortunately, there are steps you can take to dissuade your pet from swatting away all your hard work.

As Lifehacker reports, an elaborate skirt is the key to a cat-friendly tree. If a cat loves the soft, fluffy material beneath the tree, it may lose interest in the branches overhead. A different approach is to use the skirt as an opportunity to create an uninviting barrier between your cat and the tree. It's hard to mess with ornaments when they're hanging above a layer of tape laid out sticky-side up, or even a bed of pinecones if you want something that looks more natural.

Some curious cats can't be deterred by a few obstacles in their way. For these cases, PetCareRx recommends using a safe cat repellent. There are many smells cats can't stand, like bitter apple, citronella, potpourri, and even Vicks VapoRub. You can either spray pine cones or cotton balls with these scents and tuck them around the tree, or spray them directly onto the branches. Your cat will suddenly be repulsed by the shiny new object in the living room, plus your tree will smell a little more festive—especially if it's fake.

Even after taking these precautions, it helps to have a few more safeguards in place. Limiting ornaments to the top half of the tree where they'll be out of kitty's reach, and securing them with strings instead of wire hooks, means they're less likely to end up on the ground or in your pet's paws. Location is also crucial—setting up your tree right next to a sofa or another piece of furniture your cat likes to climb on is like inviting him to use it as a launchpad.

If you're thinking of skipping the traditional tree altogether this year, here are some regional alternatives.

[h/t Lifehacker]

Treat Your Achy Back to a Cozy, Vibrating Sloth Pillow This Winter

Smoko
Smoko

Battling your way through the biting winds of winter just to get to your office or run a simple errand—even if you’re just dashing a few yards to and from your car—can make your body feel like it’s been through an actual battle. And while cold weather definitely justifies curling up on the couch under a weighted blanket for hours on end, sometimes a regular throw pillow just isn’t enough to soothe your stiff muscles.

Smoko’s plush boo pillow from Urban Outfitters ($49), however, just might do the trick. Not only does it have a fleece exterior, it also vibrates: Just press the power button on the right arm, and the pillow will give you a subtle, relaxing massage to sink into while you binge-watch whatever television series your friends won’t stop talking about. According to PopSugar, it comes with three AA batteries, so you don’t have to worry about bundling back up for a last-minute trip to the convenience store after you realize the only batteries you have are in your TV remote.

The smiling sloth face on the front gives you the impression that you’re being hugged by the world’s cutest, coziest arboreal mammal. There’s also a handle on the top of the pillow, so you can easily relocate from the couch to your bed whenever you feel like it.

In short, the sloth-themed pillow might make you actually look forward to hearing your local meteorologist drop the term “wintry mix” in the forecast. And, at $49, it’s an ideal gift for anyone on your list who loves sloths and/or enjoys indulging in sloth-like behavior.

You can get one (or more) from Urban Outfitters here—and, for the full effect, why not pair it with a nice ugly Christmas sweater? Here are our 11 favorites.

[h/t PopSugar]

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