# Wasps Have the Ability to Use Logic, According to a New Study

iStock.com/Antagain

Your reaction to wasps probably consists of mild panic over a possible sting, followed by a quick escape indoors and concern over whether a nest is taking up residence on your property. New research into their behavioral processes may not minimize that reaction, but it could give you some newfound respect for these winged wonders. They're not only smart, but they might even be better at deducing logic than some humans.

A recent study by researchers at the University of Michigan and published in the journal Royal Society Biology Letters took 40 wasps (of the Polistes dominula and Polistes metricus species) and put each one of them into a rectangular container that featured one of five different colors at each end. Each color was labeled from A to E, though that was more to assign the colors a hierarchy for the human observers.

Researchers attempted to educate the wasps on the sequence of colors, with boxes labeled A and B, B and C, C and D, and D and E. An electric shock was housed under the later letter of the alphabet in each pair. If a container had colors labeled B and C, for example, the shock would be under the C. In this way, the wasps learned which color was "better." Blue was better than green, and green was better than purple. But could the wasps understand blue was better than purple?

To find out, the wasps were then placed in containers with colors marked B and D and A and E. In order to avoid getting a shock, the wasps would have to understand a color higher up in the letter ranking was associated with the shock. Over 65 percent chose B over D, better than chance, and A over E. (The latter was an easier decision, as E always delivered a jolt.)

This kind of reasoning is known as transitive inference, or the ability to take two separate bits of information and draw conclusions. The wasps knew B delivered a shock over A, and that D delivered one over C, but not that D delivered one over B. They had to extrapolate that based on independent experience.

The report is said to be the first indication invertebrates can use logical deduction. It might be related to the wasp hierarchy, where the insects are confronted with figuring out who holds dominant roles in their society.

This isn't the first time wasps have impressed scientists, either. An earlier study showed that they can identify facial patterns in other wasps, and recognize them during subsequent encounters.

[h/t New Scientist]

# 10 Juicy Facts About Leeches

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.

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.”

# 9 Facial Reconstructions of Famous Historical Figures

A facial reconstruction of King Richard III unveiled by the Richard III Society in 2013
Dan Kitwood/Getty Images

Why look at a painting of a historical figure when you can come face to face with one? Forensic facial reconstruction using scans of skeletal remains allows researchers to create 3D models of the face through a combination of science, history, and artistic interpretation. The results may be somewhat subjective, but they’re fascinating anyway. Here are nine facial reconstructions of famous people.

## 1. Richard III

In 2012, King Richard III’s skeleton was found below a parking lot in Leicester, England, where in 1485 he was hurriedly buried after dying in battle. A reconstruction (above) shows a young man, only 32 years old, with a gentle, approachable face. It’s a far cry from the child-murdering villain portrayed by Shakespeare and other writers. One thing they said does seem accurate, however: The skeleton had a curved spine from scoliosis, suggesting that Richard’s humpback may have been real.

## 2. Bach

J.S. Bach’s bust has sat on innumerable pianos for centuries, but he only posed for one portrait in his lifetime. So this reconstruction of his face—which was taken from a bronze cast of his skull—offers an interesting glimpse into the man beneath the 18th century wig. You get the same thick neck, underbite, and stern brow you see in the painting, but the reconstruction’s friendly, confused stare lacks the soul of the real man … and his music, for that matter.

## 3. Shakespeare

Apparently, no one knows anything about Shakespeare for sure—his hair color, his sexual orientation, how he spelled his name, whether he liked his wife, etc. Some people aren’t even sure whether he wrote his plays or not. So this rendering, taken from a death mask found in Germany, is bound to be controversial. But if it is Shakespeare, it’s pretty intriguing. It shows a man who suffered from cancer and had a sad, soulful face.

## 4. Dante

Maybe it’s because The Divine Comedy dealt with the ugliness of sin that Dante Alighieri is usually depicted as unattractive, with a pointy chin, buggy eyes, and enormous hooked nose. But a reconstruction done from measurements of the skull taken in 1921—the only time the remains have been out of the crypt—reveals a much more attractive Dante. The face has a rounder chin, pleasant eyes, and smaller nose than previously thought. It’s a face with character.

## 5. King Henri IV

The mummified head of France’s King Henri IV was lost after the French Revolution until a few years ago, when it showed up in a tax collector’s attic. In his day, Henri was beloved by everyone except the Catholic fundamentalists who murdered him in 1610. The hard-living king looks a bit old for his 56 years, but there’s a twinkle in his eyes. What the model cannot show, however, was how much the king stank—apparently he smelled of ”garlic, feet and armpits.”

## 6. Cleopatra’s Sister

Cleopatra hated her half-sister Arsinoe IV so much she had her dragged out of the temple of Artemis and murdered. In 2013, researchers said they had discovered what may be Arisone’s body, based on the shape of the tomb, carbon dating, and other factors. The resulting facial reconstruction shows a petite teenager of European and African blood. And yeah, maybe this is closer to what Arsinoe would look like if she were trapped in The Sims, but since Cleopatra’s remains are long gone, this may be the closest we get to knowing what she looked like.

## 7. King Tut

King Tutankhamun, whose famous sarcophagus has traveled far more than the “boy king” did in his 19-year lifetime, had buckteeth, a receding chin, and a slim nose, according to 3D renderings of his mummy. His weird skull shape is just within range of normal and was probably genetic—his father, Akhenaten, had a similarly shaped head. Tut’s body also had a broken leg, indicating he may have died from falling off a horse or chariot.

## 8. Copernicus

Nicolaus Copernicus, who challenged the belief that the sun revolved around the earth, died in 1543 at age 70. When his body was found in 2006 in a Polish church and confirmed by matching DNA to strands of his hair left in a book, the Polish police used their forensic laboratory to make this portrait. They made sure to include Copernicus’s broken nose and the scar above his left eye. Who knew that the Father of Astronomy looked so much like the actor James Cromwell?

## 9. Santa Claus

The remains of St. Nicholas, i.e. Santa Claus, have been in a church in Bari, Italy, since they were stolen from Turkey in 1087. This reproduction, taken from measurements of his skull, reveal that St. Nicholas had a small body—he was only 5’6”—and a huge, masculine head, with a square jaw and strong muscles in the neck. He also had a broken nose, like someone had beaten him up. This is consistent with accounts of St. Nicholas from the time: It turns out that Santa Claus had quite a temper.

A version of this list was first published in 2013.

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