The repeated use of the same spot for defecation is known as latrine behavior, or the creation of a communal dung pile called a midden. This deliberate, non-random act is a sophisticated biological strategy where waste is transformed into a medium for communication and environmental management. For many species, these designated areas serve two primary functions: exchanging complex information and maintaining the health and sanitation of their living spaces.
What is Latrine Behavior and Which Animals Use It
Latrine behavior involves the habitual deposition of feces, and sometimes urine, at a specific, often exposed, location that is frequently revisited by one or more individuals. The resulting accumulation, or midden, can vary dramatically in size and structure depending on the species and its habitat. These communal toilets are widespread across the animal kingdom, appearing in mammals ranging from small rodents to megafauna.
The white rhinoceros is a prime example, creating massive middens that can be several yards across, used by multiple rhinos within a territory. Individual rhinos often scrape their hind feet in the pile after defecating, spreading the scent and physically marking the area. The European badger establishes boundary latrines, which are small, shallow pits dug around the edge of its territory to demarcate its clan’s range.
North American raccoons are well-known for their latrines, typically found in elevated locations like the base of trees, on logs, or rooftops. These sites are used communally by multiple raccoons and contain a large volume of droppings. The wombat provides a more unusual example, defecating distinctive cube-shaped pellets that it stacks on prominent rocks or logs to create conspicuous latrines. This unique shape prevents the droppings from rolling away, ensuring the message remains in a highly visible location.
Defecation as a Form of Communication
For many animals, latrines function as a biological message board, transmitting complex chemical signals to neighbors and rivals. The primary purpose of these middens is territorial marking, where the accumulated scent warns other individuals that a specific area is occupied. The sheer volume and frequency of deposition at a latrine can signal the number of animals in a group or the length of time a territory has been claimed.
The chemical messages embedded in the feces go beyond boundary markers, providing detailed information about the sender’s identity and status. Feces often contain pheromones and other chemical compounds that reflect an animal’s health, diet, and reproductive state. The wombat’s stacked latrines are thought to act as a form of social media, where the chemical signature communicates an individual’s age, sex, and breeding readiness.
In species like the spotted-tailed quoll, a solitary marsupial, latrines act as a communication hub, with deposition rates increasing during the breeding season. This allows individuals to advertise their presence and find mates without direct, potentially dangerous, physical encounters. Many mammals possess specialized scent glands, such as anal glands, that coat the feces as they are expelled, enriching the chemical cocktail. This passive communication is valuable for nocturnal or solitary species, allowing them to monitor their environment even when others are not physically present.
The Role of Latrines in Maintaining Health
Beyond communication, the deliberate isolation of waste in a latrine is a form of sanitation behavior that helps manage health and prevent disease. The benefit is keeping the main living area, such as a burrow, den, or nest, clean and free of contamination. This is important for species that spend extended periods in a single location, like badgers or rabbits, where accumulated waste could quickly become a hazard.
By concentrating feces away from feeding and sleeping areas, animals effectively break the life cycle of many common parasites. Internal parasites, such as roundworms, rely on a fecal-oral transmission route, meaning their eggs must be ingested from contaminated ground or food to infect a new host. Using a latrine isolates these parasite eggs, reducing the chance of self-infection or transmission to other group members.
The danger of failing to isolate waste is illustrated by the risk posed by raccoon latrines, which are often heavily contaminated with the eggs of the Baylisascaris procyonis roundworm. This concentration of infectious material highlights the hygienic function of a latrine: to minimize the exposure of the host animal to its own pathogens. For species that graze, such as horses or antelope, using dedicated latrine sites prevents the contamination of their food supply.