What amazing insects literally eat poop but still inspired the ancients?
Dung beetles!
Ladies and Gentlemen, The Beetles
Before we begin, I want to say that dung beetles can be as fascinating as they are ‘gross’. By the end of this article, I hope maybe you will agree.
Dung beetles are insects named for poop, because they live in, feed on, raise their young in, and otherwise live their lives around animal waste. They are also sometimes referred to as Tumblebugs, which might catch on if they had a better marketing department.
They all come from the order Coleoptera, but from there things get complicated. Primarily, what are referred to as dung beetles come from the superfamily Scarabaeoidea (scarab beetles) and two different subfamilies; Scarabaeinae and Aphodiinae, but the name dung beetle gets thrown around quite liberally and can encompass earth-boring dung beetles from the superfamily Geotrupidae as well. For us purists, the doodoo-eaters from Scarabaeinae are the true dung beetles, best exemplifying the dung beetle life. There are more than 5,000 species of Scarabaeinae alone.
Nature’s Sanitary Engineers
Dung beetles exist on every continent but Antarctica and in diverse climates, including forests, grasslands, and savannas—wherever it’s not too cold or too dry. Their presence has been found to be essential almost everywhere they are found. The burying and consumption of animal dung breaks it down and makes it digestible to other organisms, improving nutrient cycling and enriching soil. They are so good at it that the American Institute of Biological Sciences estimates that in the United States alone 380 million dollars is saved, per year, through their efforts.
They are, however, picky eaters, and the importation of livestock around the world has been found to be a dicey affair without the existence of an appropriately appetited beetle. In Australia, for instance, the “Australian Dung Beetle Project” was launched to introduce cowpie enthusiasts from Europe and South Africa to deal with cattle waste. In addition to improving pastures, they are credited with lowering the incidence of bush fires by up to 90%. Overall, data has been inconclusive about the impacts of importation, but this can be seen as an example of unintended consequences, in that the importation of foreign cattle necessitated further intervention.
But . . . Why?
Nutritionally, animal dung provides everything a beetle needs, and for most dung beetles other food or drink is unnecessary.
Dung beetles are classified by three modes of poop management. “Tunnelers” like to provision and bury poop where it lays, and “dwellers” prefer to live and raise their young right in the pile. But historically, the dungbeetliest dung beetles are the “rollers,” who form balls of manure using a shovel-shaped head and paddle-shaped antennae, then push them away using their hind legs to bury them.
If all has gone according to plan, the male beetle might impress a mate with his dung-sculpting skills, enticing a female to come with him. Upon finding soft soil, they will bury the ball, and each other, and feed throughout the summer. If things go really well, they will create a “brooding ball” and the female will lay eggs inside it. The larvae will hatch and spend their entire young lives feeding inside the ball, until ready to pupate and emerge as adults.
Have You Ever Danced with a Beetle in the Pale Moonlight?
It turns out that dung-rolling is a competitive sport, and quite a few beetles at the pile can’t be bothered to sculpt their own balls. Up until the 19th century it was believed that a beetle struggling to roll his poop could count on his friends to help, until French naturalist Jean Henri Fabre proved that wasn’t the case, and that quite a few beetles will hang around solely to hijack another beetle’s hard work.
By necessity, rollers travel in a straight line. For years, some beetles were observed to stop every so often and “dance” atop their poop balls, leading researchers to. . . let me check my notes here. . . fit them with tiny hats? Yes, you read that correctly. They outfitted African Dung Beetles with tiny hats to block their view of the heavens. By doing so, they concluded that dung beetles, who could not find their way while wearing the hats, navigate according to the alignment of stars in the Milky Way. Other species have been shown to navigate by moonlight or clusters of bright stars.
Not all dung beetles are dancing with the stars, though. Another experiment, in which beetles were fitted with . . . shoes, conclusively proved that sometimes beetles dance atop poop because the ground is hot. Science and fashion for the win!
Watch some of these determined beetles in action:
Now It Gets Deep
Egyptian hieroglyphics use an image of a beetle, which roughly translates as “to transform” or “to come into being.” The dung beetle has been linked to Khepri, the God of the Rising Sun, due partially to the mistaken belief that all dung beetles were male and reproduced by impregnating… their dung balls. This idea of self-creation, literally coming from nothing, further developed into a belief that Khepri renewed the sun each day, forming a ball and carrying it across the sky, journeying through the “other world” after sunset.
The scarab, in fact, is ubiquitous in Egyptian art, and it has been speculated that the layout of Egyptian tombs in the old kingdom, with a vertical shaft and horizontal passage, is modeled after the ball in which the dung beetle lays its eggs.
A Few More Facts
A few more fun facts for our fecal-loving friends:
- Dung balls the size of oranges from 30 million years ago prove that the dung beetle has been around an exceptionally long time.
- Some species from India make very large manure balls which they cover with clay, which were mistakenly believed for years to be cannonballs.
- The six five-segmented legs found on many beetles (with others having four) have been associated with the 30 days in a month.
Further exploration, starting with the links below, is highly recommended. But in concluding our deep dive into the dung, I would like to take a moment to recognize dung beetles’ tremendous importance in creating healthy soils and healthy ecosystems. Recent experiments show that dung beetles of all varieties are essential to maintaining a healthy climate. In regions with outdoor livestock grazing, the expedient removal of manure by these creatures has been demonstrated to reduce greenhouse gas emissions and methane production by a significant margin. These creatures are not only fascinating, but truly necessary.
Rolling away now,
Mike
Mike Conway is a part-time freelance writer who lives with his wife, kids, and dog Smudge (pictured) in Northern Virginia.
Sources:
Dung beetle – Wikipedia
Dung Beetle (nationalgeographic.com)
10 Fascinating Facts About Dung Beetles (thoughtco.com)
Dung beetle | Adaptations, Behavior & Diet | Britannica
Dung Beetle | San Diego Zoo Animals & Plants
Why isn’t the world covered in poop? – Eleanor Slade and Paul Manning
Bio4Climate Resources on Dung Beetles (Search on ‘dung beetles’)