Animal scat can be roughly sorted by three features: its shape (tubular, pellet, or patty), its diameter and length, and the visible material inside it (hair, bone fragments, seeds, insect parts, or plant fiber). Together, these clues narrow the list of possible species considerably, but they rarely give you a definitive answer on their own. DNA-confirmed studies of wild scat consistently show that even experienced field biologists misidentify droppings at surprisingly high rates, so what follows is best treated as a strong first pass rather than a final verdict.
Shape as a Starting Point
The broadest sorting rule is diet. Carnivore scat tends to be tubular and tapered at one or both ends, often dark in color, and frequently twisted or ropy in texture. Herbivore scat is either pellet-shaped (deer, rabbits, goats) or arrives as large, formless patties (cattle, bison, horses). Omnivore scat sits somewhere in between and can change shape dramatically from day to day depending on what the animal has been eating. A bear feeding on berries in August will leave a loose, seed-filled pile that looks nothing like the compact, hair-laden cylinder it deposits after scavenging a carcass in spring.
Within the carnivore category, canid scat (wolves, coyotes, foxes) is usually segmented and may have a chalky white appearance when old, because the calcium from digested bones bleaches it over time. Felid scat (bobcats, mountain lions) is also tubular but often blunt-ended and frequently buried or partially covered with soil and leaf litter, a behavior inherited from domestic cats. Mustelid scat (otters, weasels, mink) tends to be dark, fishy-smelling, and deposited in conspicuous spots near water. Raccoon scat is blunt-ended and often deposited in communal “latrines” at the base of trees or on flat surfaces like logs and rooftops.
Why Diameter Alone Is Unreliable
Size is the second feature people reach for, and it helps, but the overlap between species is far larger than most field guides suggest. A study that DNA-tested Mexican gray wolf and coyote scats found that diameters overlapped by about 79 percent, with wolf scat ranging from roughly 16 to 36 mm wide and coyote scat from about 17 to 28 mm. Of 45 scats that field workers would have called wolf droppings based on location and smell, DNA showed that 42 percent actually belonged to coyotes. Going the other direction, nearly half of what looked like coyote scats by the diameter-under-30-mm rule turned out to be wolf scats.
1Wildlife Society Bulletin. Differentiating Mexican gray wolf and coyote scats using DNA analysisA separate study on red wolves and coyotes found that only scats 29 mm or wider were at least 95 percent certain to be red wolf, while only scats 14 mm or narrower could be confidently assigned to coyotes or hybrids. Everything in between was ambiguous.
2Wildlife Society Bulletin. Diameter thresholds for distinguishing between red wolf and other canid scatA broader modeling effort that tried to separate bobcat, coyote, and gray fox scat using a dozen measurements, including diameter, mass, and chemical composition, achieved only about 62 to 71 percent accuracy depending on the statistical method. That is better than a coin flip, but not by a comfortable margin.
3Wildlife Biology. A morphometric modeling approach to distinguishing among bobcat, coyote and gray fox scatsThe practical lesson is that diameter is most useful at the extremes. A pellet the size of a peppercorn is clearly rodent, not canid. A tubular scat over 30 mm wide in North American forests is almost certainly from a large canid or a bear, not a fox. In the middle range, though, you need additional evidence.
What the Contents Tell You
Breaking apart or examining the surface of a scat sample often reveals more than shape and size combined. Carnivore and omnivore droppings frequently contain visible hair, feather fragments, bone chips, insect exoskeletons, or seed coats. The type of hair or bone can narrow down what the predator ate and, by extension, where it fits in the food web, which itself constrains the candidate species list.
Here are some of the more common visible contents and what they suggest:
- Hair and bone: Strong sign of a carnivore or omnivore. Fur color and texture can sometimes indicate prey species. Bone fragments often appear white or chalky and give scat a rough, gritty texture.
- Seeds and fruit pulp: Common in omnivore scat (bears, foxes, raccoons, coyotes) and some frugivorous species. Berry seeds are often intact because they survive digestion.
- Insect parts: Shiny wing casings or exoskeleton fragments point to insectivores (bats, shrews, armadillos) or omnivores with a seasonal insect diet.
- Plant fiber and grass: Dominant in herbivore droppings. Deer pellets, for example, are almost entirely compressed plant matter. Large herbivore patties from cattle or elk are fibrous throughout.
- Fish scales or crayfish shell: Typical of otter, mink, or raccoon scat deposited near waterways.
A study of carnivore scat in Mediterranean forests found that over half of all droppings contained seeds. Red fox scat was especially seed-rich, with about 64 percent of samples containing seeds, while stone marten scat carried seeds roughly half the time.
4Elsevier / Basic and Applied Ecology. Seed dispersal by carnivorous mammals into burnt forests: An opportunity for non-indigenous and cultivated plant speciesThe presence of seeds is worth noting even when your goal is just to identify the animal, because many field guides categorize foxes and coyotes as strict carnivores. In reality, fruit is a substantial part of their diet during certain seasons. If you find a tubular scat full of berry seeds and assume it must be from an omnivore like a bear or raccoon, you may overlook a fox entirely.
Herbivore Pellets and the Rabbit Exception
Most people can recognize deer pellets: small, dark, oval nuggets usually found in clusters. Elk and moose pellets are similar but larger, sometimes slightly elongated. Goat and sheep pellets look much like deer droppings and can be difficult to distinguish without context about what species are present in the area.
Rabbit and hare scat also takes pellet form, but with an interesting twist. Rabbits produce two types of fecal output. The type you see scattered on the ground is the “hard feces” variety: small, dry, round pellets made mostly of indigestible fiber. As these pellets pass through the colon, water and nutrients are reabsorbed, leaving them dry and hard with no mucus coating. The second type, called cecotrophs, are softer, darker, mucus-coated clusters produced from partially fermented material in the cecum. Rabbits eat cecotrophs directly from the anus, so you almost never encounter them in the field.
5Veterinary Clinics: Exotic Animal Practice. Rabbit gastrointestinal physiologyIf you do find soft, greenish-black, grape-like clusters of rabbit droppings, it usually means the rabbit was stressed, ill, or unable to reingest them normally. The hard pellets you typically find outdoors are uniform, round, and roughly the size of a dried pea, which separates them from deer pellets, which tend to be more ovoid and slightly larger.
Placement, Location, and Deposition Behavior
Where you find scat matters almost as much as what it looks like. Many species deposit droppings in predictable locations, and that context can break a tie when the physical features alone are ambiguous.
European badgers, for instance, dig shallow pits called latrines and return to them repeatedly. These latrines are spaced regularly across a group’s territory, with those along the borders kept fresher and more consistently stocked than interior ones. The spacing pattern appears to matter more to the badgers than the total amount of feces at each site, suggesting the latrines function as territorial markers.
6Ecosphere. Latrine marking patterns of badgers (Meles meles) with respect to population density and range sizeRaccoons also use communal latrines, often on flat, elevated surfaces such as fallen logs, large rocks, or the flat roofs of outbuildings. Finding a pile of blunt-ended, seed- or insect-flecked scat atop a log is one of the more reliable field signs for raccoons. River otters deposit scat, called spraint, at prominent spots along waterways like bridge abutments, exposed boulders, and dock pilings. The fishy smell is distinctive even at a distance.
Canids and felids behave differently. Wolves and coyotes often leave scat at trail junctions, on elevated surfaces, or along the centerline of paths and roads, where the droppings serve as scent markers for other individuals. Bobcats may scrape soil over their scat, or they may leave it exposed at trail intersections, depending on whether they are marking territory or simply passing through. Mountain lion scat is more consistently buried or covered.
Smell as an Underappreciated Clue
Most guides understandably focus on visual characteristics, but odor can be genuinely useful if you have the stomach for it. Canid scat often has a distinctive musky smell that differs from the sharper, more ammonia-like scent of felid droppings. Otter spraint is famously described as smelling like freshly mowed grass or jasmine tea by some observers, though others are less charitable. Bear scat smells strongly of whatever the animal has been eating, which makes fruity-smelling scat during berry season a strong indicator.
Analysis of wild Iberian wolf scat found high proportions of strongly odoriferous chemical compounds, including heterocyclic aromatics, aldehydes, and low-weight fatty acids, which together suggest that feces play an active role in chemical communication between wolves.
7Biochemical Systematics and Ecology. Chemical scent constituents in feces of wild Iberian wolves (Canis lupus signatus)For the field naturalist, the takeaway is that the smell of scat is not random; it has been shaped by the same evolutionary pressures as the animal’s marking behavior. Species that use scat for territorial signaling tend to produce more pungent droppings and deposit them in more conspicuous locations.
What Scientists Extract from Scat Beyond Identification
If you are identifying scat for a research project, a trail-camera survey, or a wildlife management plan, it helps to know how far modern techniques can push the information locked inside a dropping. Visual identification is the first pass. After that, the science gets considerably more powerful.
DNA analysis from scat is now a standard method for monitoring mammal populations and is being extended to reptiles. Researchers have successfully extracted genotype-quality DNA from surface swabs of naturally deposited, sun-dried tortoise and chuckwalla scat under harsh desert conditions.
8PubMed Central. Scat as a source of DNA for population monitoringDiet reconstruction has also gone molecular. Fecal DNA metabarcoding extracts and sequences short DNA fragments from partially digested food items in a dropping, revealing exactly which plant or animal species the depositor consumed. The technique is powerful for qualitative identification of dietary species but still struggles with accurate quantification. A controlled feeding trial with goats, for example, found that fecal DNA metabarcoding reliably detected which plant species the animals had eaten but produced estimates of dietary proportions that differed from the known amounts consumed.
9Rangeland Ecology & Management. Evaluating Fecal DNA Metabarcoding to Estimate the Dietary Botanical Composition of GoatsProtocols for this kind of work, from field collection through DNA extraction and sequencing, are now well documented and increasingly accessible to conservation programs beyond the largest research institutions.
10PubMed Central. Dietary DNA Metabarcoding From Animal Fecal SamplesStress hormones are another data layer. Cortisol and related glucocorticoids are metabolized by the liver and excreted in feces, so scat can serve as a non-invasive window into an animal’s physiological stress levels.
11PubMed Central. Blood cortisol and faecal cortisol metabolite concentrations following an ACTH challenge in unanaesthetized brown bears (Ursus arctos) One caveat for researchers is that exposure to sun, rain, and microbial activity can alter hormone concentrations in a sample after it has been deposited, so timing and storage conditions matter.12Scientific Reports. Noninvasive measures of physiological stress are confounded by exposure
Safety Around Wild Scat
Scat identification is usually a look-but-don’t-touch exercise, and keeping it that way is wise. Animal feces can transmit a range of pathogens to humans, including bacteria like Salmonella and Campylobacter, parasites like roundworms and Giardia, and in some cases viruses. Safe practices focus on avoiding direct contact, washing hands thoroughly after any exposure, and not eating or drinking near areas of heavy scat accumulation.
13PubMed Central. Pathogens transmitted in animal feces in low- and middle-income countriesRaccoon latrines deserve special caution. Raccoon scat is the primary environmental source of Baylisascaris procyonis, a roundworm whose eggs can remain infectious in soil for years and, in rare cases, cause serious neurological disease in humans. If you encounter a raccoon latrine on your property, do not sweep or vacuum the area, as this can disperse eggs. The eggs are resistant to most disinfectants and are best destroyed by flame or boiling water applied directly to the contaminated surface.
Dried bat guano in enclosed spaces like attics or caves can harbor Histoplasma capsulatum, a fungus that causes respiratory infection when spores are inhaled. If you need to clean up large accumulations of bat or bird droppings, wetting the material first and wearing an N95 respirator reduces the risk considerably.
Ancient Scat and What It Preserves
Fossilized feces, called coprolites, extend the logic of scat identification back millions of years. Paleontologists use the same basic framework: shape, size, and contents. A large, blocky, calcareous coprolite from the Cretaceous Two Medicine Formation in Montana was found to contain abundant conifer wood fragments, identifying its producer as a large herbivorous dinosaur. Under the microscope, the coprolite contained a kerogen made partly of tiny vesicles interpreted as residues of bacterial cells. The bacteria appear to have induced the early mineralization that preserved the coprolite in the first place, creating calcified barriers around the organic material that protected it from decay over roughly 75 million years.
14PALAIOS. Bacterial Residues in Coprolite of Herbivorous Dinosaurs: Role of Bacteria in Mineralization of FecesCoprolites from carnivorous dinosaurs, by contrast, tend to contain bone fragments and are often lighter in color and more calcium-rich, mirroring the same bone-content signatures you would look for in modern carnivore scat. The continuity is striking: the rules of shape, size, and contents that help you identify a coyote dropping on a hiking trail are the same rules that help a paleontologist figure out which dinosaur left a fossilized pellet in a Montana hillside.