Wombats produce cube-shaped poo, and explaining it won a physics prize.
An adult wombat leaves 80 to 100 neat little cubes of dung a night, which it uses to mark its territory. How a soft, rounded gut produces flat-sided droppings puzzled people for years. In 2019 the research that helped explain it won an Ig Nobel Prize in physics.
Wombats are stocky, burrowing marsupials native to southern and eastern Australia, about a metre long and weighing 20 to 35 kilograms. There are three living species: the common wombat and two hairy-nosed species, one of which, the northern hairy-nosed wombat, is critically endangered. The name comes from the Dharug language of the Sydney area and was first written down in 1798.
Their droppings are their most famous feature. Each piece is roughly a 2-centimetre cube, and wombats arrange them to mark territory and attract mates. The leading idea is that the flat sides help the cubes stack and stop them rolling away. How they are formed is not fully understood, but the intestine is thought to stretch unevenly, with stiffer and more flexible regions in its walls that shape the dung as it moves along. Patricia Yang and David Hu received the 2019 Ig Nobel Prize for Physics for their work on the question. Wombats also digest extraordinarily slowly, over 8 to 14 days, which helps them survive in dry conditions.
The rest of the animal is just as well engineered. A wombat's pouch faces backwards, so soil doesn't pile onto its young while the mother digs. Its teeth have no roots and never stop growing, like a rodent's, which suits a diet of tough grasses, bark and roots. Its rump is armoured with toughened hide and cartilage; when a predator follows it into a burrow, it blocks the tunnel with its backside, leaving the attacker little to bite. A popular story that wombats crush predators' skulls against the tunnel roof, however, has no evidence behind it.
Wombats are mostly solitary and active at dusk and night, and can live about 15 years in the wild. They were once classed as vermin, with a bounty on their heads, and their range has shrunk greatly since European settlement. The northern hairy-nosed wombat fell to about 35 animals in the 1980s; by 2021 protection had helped bring it back to around 315.
Source: Wikipedia — Wombat · Text summarised from Wikipedia (CC BY-SA 4.0)
