Dung beetles belong to the superfamily Scarabaeoidea, a diverse group of insects found on every continent except Antarctica. They rely uniquely on animal feces, or dung, which serves as the foundation for their entire life cycle. While they do eat poop, their methods of using the waste material for survival and reproduction are complex. This relationship has positioned them as nature’s recyclers, sustaining ecosystems worldwide.
Do Dung Beetles Really Consume Feces
Adult dung beetles do not chew and swallow solid fecal matter. Instead, their primary nutrition comes from the liquid, nutrient-rich “soup” extracted from fresh dung. Herbivore dung, in particular, contains undigested plant material and moisture, which the beetles filter and consume. This liquid is packed with microorganisms that have pre-processed tough cellulose fibers, making the remaining components digestible.
Adult mouthparts are adapted for sucking and lapping up liquids rather than grinding solid material. Larvae, or grubs, have stronger jaws and consume the solid dung directly. For both life stages, the feces must be relatively fresh, as dried-out dung lacks the necessary moisture and microbial activity. Beetles are selective eaters, often preferring omnivore feces due to its higher nitrogen content, which is essential for protein building.
Three Ways Dung Beetles Process Waste
Dung beetles are classified into three functional groups based on how they handle and store the dung they find. This classification reflects the method they use to move the resource away from the competition of the dung pile, allowing various species to coexist efficiently.
Rollers (Telecoprids)
Rollers are the most famous group, known for shaping dung into a spherical ball and rolling it some distance away from the original pat. They use their hind legs to push the ball, often following a straight path to prevent circling back to competition. Once a suitable spot is found, they bury the ball for consumption or reproduction.
Tunnelers (Paracoprids)
Tunnelers remain directly at the source of the feces. They dig tunnels beneath the dung pat and transport portions of the material underground. This method quickly removes the dung from the surface and stores it in chambers below, protecting it from drying out and competitors.
Dwellers (Endocoprids)
Dwellers forgo rolling and tunneling, choosing instead to live and reproduce entirely within the dung pat itself. These beetles are smaller than the other two groups, and they simply lay their eggs within the existing fecal mass. Their method is the simplest, but they must work quickly before the dung dries out or is colonized by other organisms.
Dung as a Nursery
The central purpose of interacting with feces is providing a self-contained nursery for offspring. The female lays her egg within a structure known as a “brood ball,” which is a precisely shaped mass of dung. This ball is a complete, protective, and nutritional package designed to sustain the larva from hatching through pupation.
The preparation of the brood ball is an act of parental dedication, especially among rollers. The male and female often work together to construct and bury the ball, sometimes with the female riding on top as the male rolls it. Once buried, the female lays a single egg inside, sealing the chamber with secretions to protect it from parasites and moisture loss.
Upon hatching, the larva, or grub, consumes the surrounding dung, which serves as its sole food source. This resource allows the larva to develop fully without needing to forage. This extensive parental investment ensures the next generation has the maximum chance of survival before emerging as an adult beetle.
The Essential Role of Dung Beetles in Ecosystems
The actions of dung beetles extend beyond their personal survival, enhancing environmental health. By rapidly removing and burying animal feces, they perform a large-scale sanitation service that accelerates nutrient cycling. This process returns nitrogen and other essential minerals directly into the soil, acting as a natural fertilizer that promotes plant growth.
The tunneling and burrowing activities of these beetles significantly improve soil structure, a process known as bioturbation. These underground galleries increase soil porosity, allowing for better aeration and water infiltration. This improved soil quality benefits root systems and helps prevent runoff.
The quick removal of dung is also a natural method of pest control. Unprocessed feces serve as ideal breeding grounds for various pests, including flies and parasitic worms. By eliminating this resource, dung beetles reduce the populations of these organisms, leading to healthier grazing animals and reduced disease spread. They also aid in secondary seed dispersal, as many seeds that pass intact through a grazer’s digestive system are buried with the dung, giving them a chance to sprout.