Much more than you wanted to know about wombats

Epistemic status: infected. Amateur Wombat enthusiast. Facts checked and footnoted.

AI use: research (fact-check and extra facts), review, grammar and light phrasing.

I remember very vividly how my unhealthy interest in wombats started. It was an ordinary day and I was not anticipating anything special. I was browsing YouTube and stumbled upon a video called Wombat attack inside tunnel.Back then I didn't even know what a wombat was. In the video a guy went into an abandoned pipeline in Australia and a wombat entered it right after him. The guy started freaking out like crazy and I was so confused.

Look at this ball of fur - does this look like a deadly monster causing fear and terror? It didn't to me, so I couldn't understand the reaction of the tube-goer. Apparently wombats live in burrows and have an interesting and unique defense mechanism against predators: their backside is armored, four fused bony plates under cartilage, fat and very thick skin. If a predator tries to follow a wombat into its burrow, the wombat simply turns its back and plugs the tunnel with its rump. It is unclear whether the wombat would also crush the predator if it tries to squeeze its head past the wombat. The Australian Museum and the Tasmanian government state this as fact. The one scientist who actually studies wombat rumps says there is no evidence it happens.

The guy in the video was inside a burrow-like structure and the wombat just entered after him. So now I understood all the terror. In such a situation the wombat is an immovable object. Fortunately, after fifteen minutes of being pushed by the guy, the wombat felt merciful that night (or bored), and the guy survived and posted this video. Years later I stumbled upon it and was mesmerized by the magic of wombats. This contrast between a cute rodent marsupial (as I discovered while writing this post) and a deadly killer crushing predators with its back was extremely unusual.

You cannot imagine my joy when I discovered that wombats are the only animals pooping cubes:

I know that they are not perfect cubes and have rounded corners, but none of us is infallible. A wombat is a biological creature just like us and you can't require geometric precision from it. Still, this was amusing - to stand out in such a geometric way.

The physicists who figured out the mechanism behind the cube-shaped poo got the 2019 Ig Nobel Prize in Physics "for studying how, and why, wombats make cube-shaped poo".

I've also discovered that they fart and like corn (video).

Things I did not know I wanted to know

The rest I found while researching this post.

They have pouches, and the openings face backwards. The hypothesis is that this keeps dirt out while the mom is digging.

Baby wombats are even cuter and look like a mix of a bear and a goblin (which makes you wonder about my standards of cuteness).

Their teeth never stop growing, to compensate for the wear and tear of chewing tough vegetation.

You cannot export a wombat from Australia as a pet. Only approved zoo, research, education or conservation transfers may be allowed.

I hope you've enjoyed learning about wombats, and that I was able to transmit this virus of wombat wonder and appreciation to you too.

1. "Wombat attack inside tunnel", Andrew Ucles, YouTube, 12 October 2012. The "abandoned pipeline" is a concrete drain pipe on the south coast of New South Wales, and he was in there looking for foxes.
2. The anatomy and the "no evidence" line are from Alyce Swinbourne, who studies wombat rumps, in The Guardian, 4 November 2020: the rump is "four plates fused together and surrounded by cartilage, fat, skin and fur"; on skull-crushing, "It is possible, by their physiology and everything, but there is no evidence that that is actually happening." The crushed fox skulls found outside burrows may be housekeeping: the wombat dragging out a fox that died in there and squashing the skull on the way. The legend stated as fact: Australian Museum ("it can defend itself by crushing a predator's head with its rump against the roof or wall of the burrow") and the Tasmanian government ("The wombat is also capable of crushing attackers against the burrow roof"). Wikipedia files it under urban legend.
3. The physics: P. J. Yang et al., "Intestines of non-uniform stiffness mold the corners of wombat feces", Soft Matter 17, 475-488 (2021), DOI 10.1039/D0SM01230K. "Only animal" is the team's own framing, from their 2018 conference abstract: cubic feces are "unique in the animal kingdom". The paper also concedes the corners: "The wombat feces themselves are not perfect cubes, as the corners, while distinct, are clearly rounded."
4. Ig Nobel Prize in Physics, 2019: Patricia Yang, Alexander Lee, Miles Chan, Alynn Martin, Ashley Edwards, Scott Carver and David Hu. The mechanism, from the paper in footnote 3: the cubes form in the last 17 percent of the intestine, whose wall has two stiff bands and two soft ones; when the gut contracts, the stiff parts move faster and press the corners into the drying poop. A wombat makes 80 to 100 of them a day.
5. The clip is from the BBC Two Natural World film "Kangaroo Dundee and Other Animals - Part 2", first broadcast 12 May 2016. The wombat is Pete, a southern hairy-nosed wombat, the snack is sweetcorn, and the fart is at 0:12 ("wasn't me").
6. CSIRO, "Ten things you need to know about wombats", 13 July 2022: "In wombats, the pouch faces backwards. This is likely an adaptation to prevent the pouch filling with soil when digging."
7. The joey in the video is Apari at Zoo Duisburg, Germany, filmed in April 2018 at about six months old. His mother rejected him and the keepers hand-reared him, the zoo's first wombat joey in four decades. An actual newborn wombat is a different sight: one gram and under three centimetres (NSW government).
8. Australian Museum, Bare-nosed Wombat: the incisors and molars "have open roots and continue to grow throughout the animal's life". Wombats are the only marsupial with continuously growing teeth, and the only one with a single pair of upper incisors (Sharp and Trusler 2015, PLoS ONE; San Diego Zoo Wildlife Alliance factsheet). The Tasmanian government adds that they use them "for cutting through obstructions, much like a beaver".
9. EPBC Act s 303DG(3): no export permit for a live native mammal unless it is an "eligible non-commercial purpose export". The eligible purposes are research, education, exhibition, conservation breeding, household pets, personal items and travelling exhibition (DCCEEW guide). The household-pet route is closed for wombats: the list of native species you may take abroad as a pet has six entries, all parrots and cockatoos.