Itsy-Bitsy Arachnids Use Bats as Airplanes

We humans take a lot for granted. Take air travel, for example. We often forget how much cleverness, persistence, and hard work it took to overcome the fact that we have no wings of our own.

But we aren’t the only species that soars on borrowed wings. A number of little critters hitch rides on larger animals, in a practice known as phoresy (FAWR-uh-see). Recently, scientists in New Zealand reported the first known case of a pseudoscorpion riding a bat.

Pseudoscorpions are exactly what they sound like: bugs that look like, but are not, scorpions. Like scorpions, pseudoscorpions are arachnids with armored bodies and pincers. But pseudoscorpions are teeny-tiny: the largest known species tops out at about a half inch long. And where true scorpions have formidable, venom-tipped tails, pseudoscorpions have nothing. They do have venom in their pincers, but they’re too little to do much damage to anything other than their even-smaller prey. Because they’re so small, they have a limited range—or they would, if they didn’t get clever.

Members of the pseudoscorpion family have been caught bumming rides before, using their little pincers to grab hold of another animal’s legs. “They’re sort of known as ‘nature’s hitch-hikers’,” Massey University’s Graeme Finlayson told New Scientist. “Hitch-hiking is their best way to disperse.” 

Finlayson was part of a team studying the effects of invasive species on the health of New Zealand’s native short-tailed bat (Mystacina tuberculata). “We were catching the bats and conducting thorough health checks,” he explained in an email to mental_floss this week. “This is when we first noticed the pseudoscorpions.”

The researchers found two bat-riding pseudoscorpions in one week. Both of the bugs were adult males of the species Apatochernes vastus, and both were very, very small. The body of the larger pseudoscorpion was measured at 3.33 millimeters, or about 0.13 inches. Each pseudoscorpion was found clinging to its bat’s fur.

It’s likely the pseudoscorpion hitchhikers went completely undetected by the bats, says Finlayson.

The team published their observations in the New Zealand Journal of Zoology, emphasizing the broader significance of what they found. “This discovery highlights how the protection of one species has implications for protecting lesser-known species with hitherto unidentified associations,” they wrote. 

NOTE: The species pictured above is a bat, but not the short-tailed bat.