The Beetle That Doubles as a Mass Transit System

In the tropical forests of Central and South America, a fantastic looking beetle begins its life in the drabbest of places. The harlequin beetle (Acrocinus longimanus) is named for the eye-catching splashes of black and red (or yellow) that cover its forewings. While seemingly conspicuous (some of the patterns look like something Guy Fieri would have on a bowling shirt), the designs actually help the beetles blend in with the mottled trunks and branches of trees, and it’s in the dull brown wood of fallen, decaying tree limbs that a mother harlequin beetle lays her eggs. She gnaws into the bark and deposits her eggs, usually in a batch of 15 to 20. The larvae dig deeper into the wood when they hatch, and again when they’re ready to pupate. Then they spend the next few months developing and growing into their adult form. 

Meanwhile, on those same rotting branches, the pseudoscorpion Cordylochernes scorpioides scuttles about eating small insects. Lacking the tails and poisonous stingers of their namesake, the true scorpions, these little teardrop-shaped arachnids instead take down their prey with venom secreted through their pinching claws. When a branch becomes too decayed to make a good home, or there are too many pseudoscorpions and not enough food to go around, some of these guys will have to find another dead limb to live on. But they’re tiny (often just a few millimeters long) and wingless, and the next branch might be far away. How do they get from Point A to Point B?

The answer is right underneath them. When the the fully-grown harlequin beetles chew their way back out from the branches, one of their first orders of business is to find a branch to eat bark and fungus from. Since both species are looking for the same thing, the pseudoscorpions hitch a ride on the beetles. 

After a beetle bores its way out of the wood, pseudoscorpions swarm around it and pinch its belly with their claws. Annoyed at the less than warm welcome to the outside world, the beetle flexes its abdomen and flicks its forewings, exposing its back and giving the pseudoscorpions space to climb aboard. 

As they shuffle onto the beetle, the male pseudoscorpions will make room for females, but shove each other around as they jockey for the best spots and try to keep other males from climbing on. When the beetle takes off, the pseudoscorpions secure themselves with “safety harnesses” they fashion from silk from their claws, and the males that managed to stay on the beetle compete for the attention of the female passengers and mate with them. The females usually disembark at the next branch, but the males may stay on the beetle if new females climb on and use the bug as a mobile love shack for a few days.

Big Questions
Why Do Cats 'Blep'?

As pet owners are well aware, cats are inscrutable creatures. They hiss at bare walls. They invite petting and then answer with scratching ingratitude. Their eyes are wandering globes of murky motivations.

Sometimes, you may catch your cat staring off into the abyss with his or her tongue lolling out of their mouth. This cartoonish expression, which is atypical of a cat’s normally regal air, has been identified as a “blep” by internet cat photo connoisseurs. An example:

Cunning as they are, cats probably don’t have the self-awareness to realize how charming this is. So why do cats really blep?

In a piece for Inverse, cat consultant Amy Shojai expressed the belief that a blep could be associated with the Flehmen response, which describes the act of a cat “smelling” their environment with their tongue. As a cat pants with his or her mouth open, pheromones are collected and passed along to the vomeronasal organ on the roof of their mouth. This typically happens when cats want to learn more about other cats or intriguing scents, like your dirty socks.

While the Flehmen response might precede a blep, it is not precisely a blep. That involves the cat’s mouth being closed while the tongue hangs out listlessly.

Ingrid Johnson, a certified cat behavior consultant through the International Association of Animal Behavior Consultants and the owner of Fundamentally Feline, tells Mental Floss that cat bleps may have several other plausible explanations. “It’s likely they don’t feel it or even realize they’re doing it,” she says. “One reason for that might be that they’re on medication that causes relaxation. Something for anxiety or stress or a muscle relaxer would do it.”

A photo of a cat sticking its tongue out

If the cat isn’t sedated and unfurling their tongue because they’re high, then it’s possible that an anatomic cause is behind a blep: Johnson says she’s seen several cats display their tongues after having teeth extracted for health reasons. “Canine teeth help keep the tongue in place, so this would be a more common behavior for cats missing teeth, particularly on the bottom.”

A blep might even be breed-specific. Persians, which have been bred to have flat faces, might dangle their tongues because they lack the real estate to store it. “I see it a lot with Persians because there’s just no room to tuck it back in,” Johnson says. A cat may also simply have a Gene Simmons-sized tongue that gets caught on their incisors during a grooming session, leading to repeated bleps.

Whatever the origin, bleps are generally no cause for concern unless they’re doing it on a regular basis. That could be sign of an oral problem with their gums or teeth, prompting an evaluation by a veterinarian. Otherwise, a blep can either be admired—or retracted with a gentle prod of the tongue (provided your cat puts up with that kind of nonsense). “They might put up with touching their tongue, or they may bite or swipe at you,” Johnson says. “It depends on the temperament of the cat.” Considering the possible wrath involved, it may be best to let them blep in peace.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at

Why Crows Hold Noisy Funerals for Their Fallen Friends

The next time you hear a murder of crows cackling for no apparent reason, show a little respect: You may have stumbled onto a crow funeral. Crows are among the few animals that exhibit a social response to a dead member of their species. Though their caws may sound like heartbroken cries, such funerals aren't so much about mourning their fallen friends as they are about learning from their mistakes.

In the video below from the PBS series Deep Look, Kaeli Swift, a researcher at the University of Washington's Avian Conservation Lab, investigates this unusual phenomenon firsthand. She familiarized herself with a group of crows in a Seattle park by feeding them peanuts in the same spot for a few days. After the crows got used to her visits, she returned to the site holding a dead, taxidermied crow and wearing a mask and wig to hide her identity. The crows immediately started their ritual by gathering in the trees and crying in her direction. According to Swift, this behavior is a way for crows to observe whatever might have killed the dead bird and learn to avoid the same fate. Flocking into a large, noisy group provides them protection from the threat if it's still around.

She tested her theory by returning to the same spot the next week without her mask or the stuffed crow. She offered the crows peanuts just as she had done before, only this time the birds were skittish and hesitant to take them from her. The idea that crows remember and learn from their funerals was further supported when she returned wearing the mask and wig. Though she didn't have the dead bird with her this time, the crows were still able to recognize her and squawked at her presence. Even birds that weren't at the funeral learned from the other birds' reactions and joined in the ruckus.

Swift was lucky this group of crows wasn't particularly vengeful. Crows have been known to nurse and spread grudges, sometimes dive-bombing people that have harmed one of their own.

[h/t Deep Look]


More from mental floss studios