7 Disgusting Things Butterflies Eat

iStock
iStock

"Butterflies?” you’re thinking. “But they’re so … fluttery!” And you’re right. They are very fluttery. But their eating habits are revolting.

1. MUD

Let’s start at the beginning. In kindergarten, you were taught that butterflies are nectar feeders, sipping their sugary meals from flowers. This is still mostly true. But nectar is only one food group, and those other nutrients have to come from somewhere.

After a rainstorm, it’s not uncommon in certain areas to see a whole mess of butterflies sitting on the ground, sucking up mud. This practice is known as “mud-puddling” or simply “puddling,” and scientists believe certain butterfly species do it to round out their salt, nitrogen, protein, and amino acid intake.

Naturally, mud is just the beginning.

2. AND 3. SWEAT AND TEARS

If you’ve ever visited a butterfly house, you’ve likely seen some delighted small child with a butterfly on her arm. “He likes me!” she says. Delighted Small Child is mistaken. It’s not her friendship he’s after, but her precious, precious sweat. Or maybe he's interested in her tears: In 2014, one butterfly was observed drinking the tears of a sunning spectacled caiman, and photo evidence shows they drink the tears of tortoises, too.

Delighted Small Child might have been wrong about the butterfly liking her, but she probably was not mistaken about the butterfly’s sex, however: Most puddlers are males. Scientists believe that for most butterflies, the sodium goes straight to the sperm, which is then given as a “nuptial gift” to the female, giving the future offspring a better chance of surviving.

4. URINE

Butterflies love urine—“a fact taken advantage of by collectors,” writes the author of the Handbook for Butterfly Watchers. Some species of butterfly will even consume their own bodily fluids: They'll secrete a liquid onto dried up sweat or a dried puddle of a larger animal’s urine so they can lap up the freshly dissolved minerals.

5. AND 6. BLOOD AND POOP

Back to the butterfly house. If Delighted Small Child injures herself, her helpful butterfly buddy will be there to help clean up the blood. By drinking it.

From a butterfly’s perspective, larger animals like humans are probably just big restaurants. And what leftovers! Animal poop is full of all kinds of helpful nutrients, which butterflies will feast upon when given the chance.

7. DECAYING FLESH

You know what else is full of nutrients? Dead bodies!

Rotting animal flesh is a huge butterfly favorite [PDF]—so much so that researchers have begun baiting tropical butterfly traps with shrimp heads, chunks of dead snake, and prawn paste. Texture is key; since butterflies have no teeth, they can essentially only "lick" the rotting meat. “Traps were baited and checked for cycles of five days, with extra bait added each day to ensure a range of decay,” wrote one scientist in her report [PDF]. Butterfly researchers really don’t get enough credit.

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.”

22 Weird Jobs From 100 Years Ago

Metal Floss via YouTube
Metal Floss via YouTube

Before everyone started working in tech, people actually had their choice of eclectic and strange vocations that put food on their old-timey tables. Discover what lamplighters, lectores, and knocker-uppers did back in the day as Mental Floss editor-in-chief Erin McCarthy runs down 22 Weird Old Jobs from 100 Years Ago.

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