Most people will never see a cave cricket—so why should we care about them?

If you're not an entomologist or avid caver, you can be forgiven for not hearing of cave crickets: most Australians will go their entire lives without seeing one of these spindly insects. That’s because they’re commonly found in environments like caves, abandoned mineshafts, and even underground tubes formed by long-gone lava flows. In wetter environments like rainforest, they can also be found under rock shelters or in animal burrows. Anything dark and dank is fair game for these critters.

A cave cricket (Australotettix montanus) at Oaklands Falls in the Blue Mountains of NSW. Image © Perry Beasley-Hall.

Cave crickets are only distant cousins of the “true” crickets you might find in your backyard. They have elongated legs for sensing in the dark, making them look more like spiders than anything that chirps—and for that matter, their total lack of wings mean they lost the ability to chirp long ago. They're also completely unable to hear, probably relying on vibrations in cave walls instead.

So, why care about cave crickets at all? Entomologists study these animals because they sit in an important space in the subterranean food web. As scavengers, they're responsible for cleaning up dead animals, decaying vegetation, and bat guano. As predators, they actively hunt other invertebrates and even engage in cannibalism if times are tough. As prey, they support communities of cave spiders and harvestman through their bodies, eggs, and waste. This is what we consider a "keystone" species: one that has a disproportionately large impact on its environment compared to its abundance. Cave cricket populations have been associated with higher biodiversity in caves, keeping these environments healthier overall. If we want to preserve our caves, we need to focus on conserving species like these.

Unfortunately, Australian cave crickets are at risk of extinction from mining, tourist activities, and climate change, with anecdotal declines observed nationwide. If we want to preserve these animals, it's important to understand if a cave cricket colony is a population of an existing, widespread species or an entirely new species itself. This is because if that colony is lost, it could spell the difference between the extinction of one population of many compared to that of an entire species.

To combat this, we need a robust idea of how cave cricket species are related to one another, and which groups might represent new species. Dr Perry Beasley-Hall at The University of Adelaide is using DNA to do just that, sampling cave crickets Australia-wide and beyond to understand species boundaries of these weird and wonderful animals. Dr Beasley-Hall has been funded by a prestigious Australian Biological Resources Study Postdoctoral Fellowship since 2023 and her research has revealed at least 11 new species of cave crickets in Australia, with more to come. Taxonomic research such as this is fundamental if we’re to protect Australian biodiversity long into the future, particularly species are found in habitats usually overlooked in conservation planning.

You can follow updates on Dr Beasley-Hall's research on her X account here.