Digging a small pit to deposit and cover feces is an evolved practice observed across various mammal orders. This behavior is a sophisticated form of communication and hygiene management. The decision to bury waste or leave it exposed is a deliberate choice, signaling an animal’s social status, intent, or need for discretion. This behavior is fundamentally driven by two primary evolutionary pressures: reducing the risk of disease and managing scent-based messages to other animals.
Animals That Bury Waste Individually
The most recognizable practitioners of individual waste burial belong to the Felidae family, which includes domestic cats and many smaller wild species. These animals meticulously dig a hole, eliminate, and then use their paws to scrape soil, leaves, or litter over the scat immediately afterward. The main purpose of this individual act is to minimize the animal’s immediate scent profile, which is crucial for a small or medium-sized predator.
Burying waste is a survival tactic designed to make the animal less conspicuous in its territory, concealing its presence from both potential predators and prey species. Other solitary carnivores and herbivores also exhibit this concealing behavior. These include members of the Mustelidae family, such as mink and weasels, as well as woodchucks and armadillos. They all seek to hide their location from more dominant animals or hunters.
Communal Latrine Users
A distinctly different form of waste management involves the use of communal latrines, which are shared, designated areas where multiple individuals deposit their waste. While these sites often involve digging and covering, the intent is not to hide a presence but rather to establish a highly visible, shared landmark. Raccoons are a well-known example, habitually using elevated or conspicuous spots like large logs, stumps, or the bases of trees as their communal “toilets.”
The function of these latrines is often territorial, acting as a clear boundary marker that advertises the presence of a group to potential intruders. This concentration of waste serves as a long-lasting, olfactory signpost to communicate the group’s occupancy of the area. However, these communal sites can pose a public health hazard. Raccoon latrines may contain the eggs of the roundworm Baylisascaris procyonis, which can be harmful if accidentally ingested by humans or other animals.
The Biological Reasons for Burying Scat
The evolutionary drivers behind the burial instinct focus on health and communication. One significant factor is the maintenance of sanitation within a den or home range. Covering waste reduces the likelihood of parasites and pathogens spreading through the immediate environment, safeguarding the animal and its offspring and ensuring a cleaner living space.
The need for predator and prey evasion is a primary motivator, especially for smaller animals that are vulnerable to being hunted. The strong scent of feces acts as a beacon, so burying it provides a form of scent camouflage that makes it harder for a tracker to locate the animal or its den site. This is particularly important for mothers with young, who will work diligently to keep their nesting area scent-free.
The decision to bury or not bury also functions as a form of social signaling within a species. For cats, leaving scat exposed is often an aggressive display of dominance, signifying that the animal is confident enough to advertise its presence and challenge others. Conversely, burying scat is interpreted as a submissive or polite gesture, demonstrating deference to a dominant individual or a desire to avoid direct confrontation over territory.