Zoologger is our weekly column highlighting extraordinary animals – and occasionally other organisms – from around the world

Species: Apatochernes vastus, a species of pseudoscorpion

Habitat: Squirming in bat faeces and tree hollows in the forests of northern New Zealand.

What’s a tiny invertebrate with massive pincers to do? At only a few millimetres long, pseudoscorpions can struggle to get around. But jet-setting Apatochernes vastus has the answer: hitch a ride on a bat.

Like scorpions, pseudoscorpions have two large pincers, but they lack a stinging tail (see photo, above). Many can use their pincers to deliver neurotoxic venom, but they are so small that they only use it to kill the insects and larvae they eat.


While the pincers pose no threat to mammals, their size enables pseudoscorpions to hitch a ride on larger mammals. “They’re sort of known as ‘nature’s hitch-hikers’,” says Graeme Finlayson at Massey University in Palmerston North, New Zealand. “Hitch-hiking is their best way to disperse.”

Some types of pseudoscorpion have been seen cadging a ride on giant harlequin beetles in South America, and on bats in Africa and Australia. Now A. vastus has become the first pseudoscorpion to be caught stowing away on a bat in New Zealand (see photo, below).

There are only two species of native land-mammals in New Zealand, both of them bats. Because there are no native land predators in the country, many animals that originally flew spend more time on the ground, like kiwis. The lesser short-tailed bat can still fly, but also spends much of its time foraging around in leaf litter on the forest floor. This probably explains how it encounters pseudoscorpions.

The stowaways are thought to be harmless to the bats. “They just grab onto the fur and then off they go and get on their way,” says Finlayson. His observations suggest that they don’t ride for very long.

It is possible that A. vastus enjoys a range of transportation modes. “When we were in the forest we did see a pseudoscorpion on a fly, but we weren’t able to catch it to identify it,” says Finlayson. There are many pseudoscorpions in New Zealand, so it may have been a different species.

Journal reference: New Zealand Journal of Zoology, DOI: 10.1080/03014223.2015.1063517

Image credits, from top: Image courtesy of Mark Harvey at the WA Museum; George Madani