Wombats, the sturdy marsupials native to Australia, are known for a few odd traits – powerful claws, a backward-facing pouch, and an impressively tough rear end. But their strangest feature? They poop in cubes.
That’s right. Wombats are the only known animals to consistently produce cube-shaped feces. For years, scientists couldn’t explain how or why this happened. After all, their anuses are round – so where do the cubes come from?
It turns out, the answer lies deeper in the gut. What started as a bizarre bit of animal trivia evolved into a serious study in biomechanics, with findings that may even inspire new materials and soft robotics.
Here’s how and why wombats produce poop that’s surprisingly geometric – and how nature makes it work.
The Wombat: A Quick Profile
Wombats are short, stocky marsupials found across Australia and Tasmania. They average about 1 meter (3 feet) in length and can weigh between 20 to 35 kilograms (44 to 77 pounds). While they may look slow and cuddly, wombats are burrowing powerhouses, capable of digging long tunnel networks with their thick, muscular limbs.
They are nocturnal herbivores, feeding mostly on grasses, roots, and bark. Their digestion is incredibly slow – it can take up to five days for food to pass through their system. That sluggish process, it turns out, plays a key role in shaping their unusual feces.
Wombats are also known for having a rear end made of cartilage, which helps them block predators from entering their burrows. But it’s their intestines, not their backside, that hold the key to cube-shaped poop.
Why Is Their Poop Cube-Shaped?
For a long time, scientists thought the shape of the feces might have something to do with the wombat’s anus. But that theory fell apart under closer study. In reality, the anus is round – just like nearly every other mammal’s.
The breakthrough came in 2018, when a team of researchers led by Dr. Patricia Yang at the Georgia Institute of Technology analyzed wombat intestines. They discovered that the poop takes its shape inside the colon, not outside of it.
Their study, later published in the journal Soft Matter in 2021, revealed that the wombat colon has alternating stiff and flexible regions. As fecal matter slowly moves through the digestive tract, these segments apply varying pressure, squeezing the material into corners.
It’s a slow process. The wombat’s low-moisture diet and long digestion time dry out the feces as it moves. When the intestinal walls contract rhythmically – known as peristalsis – the pressure from the rigid and elastic zones sculpts the material into a distinct cube shape with defined edges.
Dr. Yang’s study used both physical intestine samples and 2D modeling to recreate the process, confirming that it’s entirely internal – no external shaping required.
What’s the Purpose of Cube Poop?
The cube shape isn’t just a weird biological accident. It has a clear functional purpose: marking territory.
Wombats are solitary and territorial animals. They use scent-marking to communicate boundaries and presence to other wombats. But dropping poop randomly on the ground wouldn’t work well – it might roll off a rock or slope.
Cubes, on the other hand, don’t roll. Their flat sides allow them to stay put on logs, rocks, or raised surfaces – which is exactly where wombats prefer to leave them.
By depositing cube-shaped feces in high places, wombats create durable scent markers that are more likely to be noticed and remain in place. It’s an elegant solution – and another reminder that form often follows function in nature.
The Science Behind It
The 2018 research team first presented their findings at a meeting of the American Physical Society’s Division of Fluid Dynamics. Their results generated global media attention – not only because of the oddity of the topic, but because of its implications.
The study, later expanded and published in Soft Matter, showed that this type of shape formation could be mimicked using synthetic materials. Their model revealed that varying elasticity and moisture levels – along with rhythmic pressure – could be used to create sharp edges and corners in soft solids.
This has potential applications in fields like biomedical engineering, soft robotics, and manufacturing – particularly where molding materials without cutting or stamping is desirable.
Smithsonian Magazine’s coverage provides a helpful overview of how the research unfolded and why it matters beyond marsupial biology.
How It’s Different from Other Animals
Most animals produce feces that are:
- Round or oval
- Amorphous (especially in soft-bodied species)
- Variable in size and shape depending on diet and water content
But wombats consistently produce around 80 to 100 cube-shaped droppings per night, especially when marking territory.
No other known animal forms solid, geometric feces internally. Some creatures (like certain beetles or rodents) may produce dry, pellet-like droppings – but nothing close to the symmetry and shape of a wombat cube.
And unlike birds or reptiles, whose excrement contains both waste and uric acid in semi-liquid form, wombat poop is dry, segmented, and solid – ideal for stacking, staying in place, and lasting for days without breaking down.
FAQ
Do wombats have cube-shaped anuses?
No. Their anus is circular like that of other mammals. The cube shape is formed inside the colon, thanks to unique intestinal elasticity and pressure patterns.
Does the shape hurt the wombat?
Not at all. The shape forms slowly over several days as food is digested. Wombats have evolved to process tough plant matter at a slow pace, which helps the cubes take shape without discomfort.
Can other animals do this?
No. Wombats are the only known species to produce cube-shaped feces naturally. Other animals don’t have the same combination of intestinal structure and slow digestion to make it happen.
Is this used for scientific innovation?
Yes. Researchers studying wombat poop mechanics have proposed new ways to design soft materials that form into specific shapes through pressure – no molding or cutting required.
How many cubes does a wombat produce per day?
Wombats typically produce 80 to 100 individual cube-shaped droppings per night, especially when actively scent-marking their territory.
Nature Gets Weird – and Brilliant
At first glance, cube-shaped poop seems like one of those weird animal facts that just exists for shock value. But the deeper you go, the clearer it becomes – it’s a perfect example of evolution solving a practical problem with elegant design.
The wombat’s digestive system is tailored to its diet, its solitary lifestyle, and its need to communicate with others without wasting energy. That means poop that stacks, stays put, and sends a message.
And for scientists, it’s a reminder that even the strangest traits can offer insight into biomechanics, materials science, and the untapped potential of natural engineering.
In the end, wombats might just be some of nature’s most unexpectedly efficient designers – one cube at a time.
Fancy more wow-facts about animals? Did you know that sharks are much more ancient than trees?
To learn something new and amazing each day, follow WowToKnow on Facebook, X, Reddit, and Telegram.
