The cracks are where the light (and life) gets in
I was out in the winter sunshine the other day. Sitting cross-legged and looking at the small world going on beneath me. I noticed a little plant growing luxuriantly from a crack in the pavers – turns out it was Red Caustic Weed (Chamaesyce prostrata). Not caustic in fact, but most assuredly red and a weed that’s common in this part of the world.
I got to thinking that as humans, we tend to view cracks in a negative light. A crack means something is broken, diminished. Damaged goods. For instance, when you say, ‘the cracks are starting to show’, rarely is that cause for celebration.
But to nature, a crack is less of a catastrophe, and more of an opportunity.
Which made me wonder… what are some critters who don’t just tolerate cracks, but rely on them?
First up is a critically endangered, sub-alpine lizard – the Kaputar Rock Skink (Egernia roomi). They’ve been sunning themselves at altitude for probably a million years, but they’re actually one of Australia’s most newly declared reptiles (officially their own species in 2019). Their entire habitat is thought to be about 30sqkm – they live only in the Nandewar Range, east of Narrabri. And these skinks rely on cracks!
During winter, they hole up in rocky cracks and crevices of Mount Kaputar’s volcanic rock and lava fields. This keeps them safe from extreme cold and from predators. In summer, the cracks are a place to wait out bushfires.
So, as far as the Kaputar Rock Skink is concerned, the refuge offered by cracks is not just a ‘nice to have’, it’s a matter of species survival.
Next on the list are the Dunnarts – specifically the endearingly named Fat-tailed Dunnart and its cousin, the Stripe-faced Dunnart (Sminthopsis crassicaudata and Sminthopsis macroura respectively). These button-cute marsupials are desert dwellers, and they too make use of cracks.
In this instance, they take advantage of the microclimates created by cracks in arid cracking clay soils. Whereas desert conditions can fluctuate wildly, cracks in the clay provide more stable conditions – evening out both temperature and humidity – which is important when you’re small and susceptible to weather extremes, as Dunnarts are.
Finally, there are our friends the Huntsman Spiders. In addition to hanging around the house and periodically freaking out any resident arachnophobes, several species of Huntsman have flattened bodies, purpose-built for fitting into cracks between rocks and under tree bark. The flattest of them all is the imaginatively titled Flat Huntsman (Delena cancerides). Also called Communal Huntsman these are rather social, share food, live in groups of up to 300, and love nothing better than to slide into tree bark for safety and a bit of R&R.
So, far from catastrophes, life’s cracks can also be opportunities, and in fact, essential.
Leonard Cohen wrote ‘There’s a crack in everything, that’s how the light gets in’ and he was right. Perhaps too, the cracks are where the LIFE gets in. At least, that seems to be Nature’s take on it.
Words and pictures by Amanda Sun.
© Amanda Sun 2026. All rights reserved.
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If you’d like to delve deeper, here are the sources I used.
National Parks and Wildlife Service (n.d.) Kaputar rock skink. NSW National Parks and Wildlife Service. Available at: https://www.nationalparks.nsw.gov.au/plants-and-animals/kaputar-rock-skink (Accessed: 18 August 2026).
Australian Museum (2026) Huntsman spiders. Australian Museum. Available at: Huntsman Spiders (Accessed: 18 August 2026).
Waudby, H.P. and Petit, S. (2017) ‘Thermoregulatory value of cracking-clay soil shelters for small vertebrates during extreme desert conditions’, Integrative Zoology, 12(3), pp. 237–249. doi: 10.1111/1749-4877.12225.
iNaturalist (n.d.) Delena cancerides (Social Huntsman Spider). iNaturalist. Available at: https://www.inaturalist.org/taxa/388489-Delena-cancerides (Accessed: 18 August 2026).