Black racers absolutely eat other snakes, and they do so regularly enough that herpetologists classify them as facultative ophiophages, meaning snake-eating is a routine part of their diet rather than a rare event. The list of species they consume includes gartersnakes, milksnakes, ring-necked snakes, earth snakes, and even small venomous species like copperheads and young rattlesnakes. But snake-eating is only one component of a broad, opportunistic diet that shifts with the racer’s age, size, and habitat, so the popular image of the black racer as a dedicated serpent-hunter deserves some correction.
What Black Racers Actually Eat
The black racer (Coluber constrictor) is one of the most generalist predators among North American snakes. Adults eat rodents, frogs, toads, lizards, birds, bird eggs, large insects, and other snakes. Juveniles tend to eat smaller prey, mostly insects, spiders, and tiny frogs, because their gape size limits what they can swallow. As they grow, the proportion of vertebrate prey in their diet increases, and that is when other snakes start showing up as meals.
The species is diurnal and relies on speed rather than ambush. Black racers actively forage, moving through leaf litter, grasslands, and forest edges during daylight hours. When they encounter a smaller snake, they strike quickly and pin the prey with loops of their body. Despite the scientific name “constrictor,” they do not kill prey by constriction the way a boa or kingsnake does. Instead, they press the prey against the ground and begin swallowing it alive. This method works well on smaller, slower-moving snakes but limits the size of snake they can safely consume.
Which Snake Species End Up as Prey
Documented prey species read like a cross-section of the small snake community in the eastern United States. Gartersnakes and milksnakes are among the most commonly reported victims, along with ring-necked snakes, smooth earth snakes, brown snakes (Storeria), and worm snakes. Racers will also eat juvenile individuals of species that grow larger than they do, so a young rat snake or a young copperhead is fair game even if the adult version would be too large to tackle.
A multi-year field study in south-central Pennsylvania investigated how the presence of Northern Black Racers influenced local snake populations. At sites where racers were present, Eastern Milksnakes were actually more abundant overall but had noticeably fewer juveniles, suggesting that racers were selectively eating younger, smaller milksnakes. Eastern Gartersnakes showed a different pattern: adult females were larger in body size at racer-present sites, and adult males were encountered less frequently. The researchers interpreted these findings as evidence that racers exert real predatory pressure on other snake species, and that the effects vary depending on the prey species’ life history and body size.1Northeastern Naturalist. Evidence of Intraguild Predation in a Snake Assemblage: Bigger Seems Better
The term the researchers used for this dynamic is “intraguild predation,” which simply means predators eating other predators within the same ecological community. All snakes are predators of some kind, so when a black racer eats a gartersnake, it is eliminating a competitor for shared food resources like frogs and insects while also gaining a meal. This makes black racers unusual among common backyard snakes; they function both as predators and as population regulators of other snake species.
Do Black Racers Eat Venomous Snakes
They can, and occasionally do, but the idea that black racers routinely hunt and kill copperheads or rattlesnakes is overstated. Black racers have no venom immunity. A bite from a pit viper could injure or kill them just as it could harm any other non-immune animal. What racers do have is speed and a willingness to eat whatever they can overpower, and that sometimes includes small venomous snakes.
The snakes most likely to be eaten are juveniles. A newborn copperhead is roughly pencil-sized, slow, and easily overpowered by an adult racer. An adult copperhead, on the other hand, is thick-bodied, well-armed, and not an easy target. So while racers are capable of eating venomous species, they are not seeking them out as preferred prey, and they are not equipped to safely handle the large adults that homeowners most want gone.
This matters because one of the most persistent folk beliefs in the southeastern United States is that having black racers on your property keeps copperheads away. The reasoning sounds logical: racers eat snakes, copperheads are snakes, so racers must eat copperheads. In practice, a black racer and a copperhead can easily share the same patch of woods without ever interacting. They have different activity patterns (racers are diurnal, copperheads are largely nocturnal or crepuscular), different microhabitat preferences, and different prey bases. A racer on your property is not a guarantee of copperhead control, and killing a racer because you mistook it for a venomous species, which happens frequently, actually removes a mildly beneficial predator from the ecosystem.
How Racers Compare to Kingsnakes as Snake-Eaters
When people think of snake-eating snakes, kingsnakes usually come to mind first, and for good reason. Eastern kingsnakes (Lampropeltis getula) are specialized ophiophages with partial resistance to pit viper venom and powerful constriction that can subdue snakes close to their own size. Kingsnakes actively seek out other snakes by following scent trails, and they can safely consume adult copperheads and rattlesnakes that would be dangerous for a racer to attempt.
Black racers approach snake-eating differently. They are generalists, not specialists. A racer moving through tall grass is just as likely to grab a toad or a mouse as it is a ring-necked snake. It eats whatever it encounters and can overpower. Kingsnakes, by contrast, are genuinely drawn to snake scent and will pass up other prey to pursue a snake meal. The practical difference for a homeowner is this: a kingsnake is a meaningfully better “venomous snake control” animal than a black racer, though neither should be relied upon as pest management.
The two species also differ in their killing method. Kingsnakes are true constrictors that coil tightly around prey and suffocate it before swallowing. Racers simply pin and swallow. This means a racer’s prey is often still alive and struggling as it goes down, which limits the racer to prey that is substantially smaller than itself. A kingsnake can handle prey closer to its own diameter because constriction neutralizes the threat first.
How Eating Other Snakes Affects Parasite Load
One consequence of eating other snakes that rarely gets discussed outside parasitology circles is the transfer of internal parasites. Snakes carry gastrointestinal helminths, including roundworms, tapeworms, flukes, and thorny-headed worms. When a racer eats another snake, it can pick up whatever parasites that prey animal was hosting, especially when the parasite’s life cycle involves being consumed by a predator to reach its next developmental stage.
A parasitological survey of 23 Northern Black Racers from North Carolina found 18 species of helminths, an impressively diverse internal community that included four types of trematodes, two cestodes, ten nematodes, and two acanthocephalans. The most common parasite was an immature physalopterid nematode found in about half the snakes, followed by the nematode Abbreviata terrapenis at roughly 43 percent prevalence.2BioOne Complete. Helminths of the Northern Black Racer, Coluber constrictor constrictor Linnaeus (Squamata: Colubridae), from North Carolina, U.S.A.
That diversity of parasites is partly a consequence of the racer’s broad diet. An insect-eating snake picks up parasites with insect intermediate hosts. A frog-eating snake picks up parasites with amphibian intermediate hosts. A snake-eating snake picks up parasites from every prey animal its prey has ever eaten, creating a kind of cascading accumulation. This does not necessarily make racers sicker than other snakes; many helminths have little obvious effect on their host at low intensities. But it does make racers useful study animals for parasitologists trying to map which parasites circulate through a particular ecosystem, because a racer’s gut is essentially a sampler of the local food web.
Why Black Racers Are Often Misidentified
Black racers are frequently confused with several other dark-colored snakes, and the confusion leads to both unnecessary fear and unnecessary killing. In the eastern United States, the species most commonly mistaken for a black racer include the black rat snake (now called the Eastern ratsnake, Pantherophis alleghaniensis), the Eastern kingsnake, the Northern cottonmouth, and in some areas, the Eastern indigo snake.
A few distinguishing features help sort them out. Black racers are slender, smooth-scaled, and uniformly matte black on top with a white or grayish chin. They are fast and flighty; when startled, they bolt. Rat snakes are heavier-bodied, often show faint patterning or a slightly keeled scale texture, and tend to freeze or coil defensively rather than flee. Cottonmouths are thick, heavy, and have a distinctly triangular head with obvious heat-sensing pits between the eye and nostril. The behavior difference alone is often the best field mark: if a black snake rockets away from you at surprising speed, it is almost certainly a racer.
The misidentification problem feeds directly into the “black snakes eat copperheads” narrative. People see a fast black snake near their house, label it a racer (or a “black snake,” a catch-all folk term), and credit it with keeping venomous snakes away. Sometimes the snake is actually a ratsnake, which has different dietary habits. Sometimes it is a kingsnake, which genuinely does eat venomous species with some regularity. The blanket term “black snake” flattens the ecology of several very different species into one story.
What Happens When You Remove Racers from an Area
The Pennsylvania study mentioned earlier offers a useful lens for thinking about this question. At sites where racers were absent, the local snake community looked measurably different: juvenile milksnakes were more common, and male gartersnakes were encountered at higher rates.1Northeastern Naturalist. Evidence of Intraguild Predation in a Snake Assemblage: Bigger Seems Better The implication is that racers, as intraguild predators, shape the age structure and sex ratios of smaller snake populations around them. Remove the racers and you may see more small snakes, which sounds like a minor ecological footnote until you consider the downstream effects.
More small snakes means more competition for the insects, frogs, and small rodents that those snakes eat. It can also mean changes to the prey base available for hawks, owls, and other snake predators. Ecosystems are connected in ways that make removing a single predator difficult to evaluate in isolation. Black racers are not a keystone species in the way that, say, wolves in Yellowstone have been described, but they do occupy a middle-predator niche that influences the community around them.
For landowners, the practical takeaway is straightforward: killing black racers because they look scary or because you assume they must be venomous removes a predator that was, among other things, eating rodents, eating pest insects, and keeping the small snake population in check. If anything, a property with healthy racer numbers likely has a more balanced small-animal community than one without them.
Seasonal and Age-Related Diet Shifts
A hatchling black racer is roughly 20 to 30 centimeters long and weighs only a few grams. At that size, its menu is dominated by invertebrates: crickets, grasshoppers, spiders, caterpillars, and beetle larvae. As juveniles grow through their first and second years, they begin adding small frogs and lizards. Snake-eating generally appears only in subadults and adults that have reached sufficient body length to overpower another snake. Most adult racers are between 90 and 150 centimeters, which gives them the size advantage needed to pin and swallow gartersnakes, earth snakes, and similar small species.
There is also a seasonal component. Racers in northern parts of their range emerge from winter dormancy in April or May and are initially hungry, eating whatever they can find. Spring and early summer tend to produce the highest feeding rates, and this coincides with the period when many small snakes are also active and vulnerable. Late summer and early fall shift the prey base toward larger insects, late-season frogs, and the occasional bird or bird egg. In the southern parts of their range, where winters are milder, racers may remain active nearly year-round, but feeding intensity still drops during cooler months.
The upshot is that snake-eating is not a constant behavior. A racer might eat another snake a handful of times per season, interspersed with dozens of meals consisting of mice, frogs, and insects. If you happen to witness a racer consuming a gartersnake in your backyard, you are watching something that is normal for the species but not something it does every day.
Living Alongside Black Racers
Black racers are nonvenomous and generally want nothing to do with people. Their first instinct when they detect a human is to flee, and they are fast enough to make good on that instinct. If cornered, they may vibrate their tail in dry leaves to mimic a rattlesnake, strike repeatedly, and musk (release a foul-smelling liquid from glands near the tail base). The bite of a racer can draw blood but poses no medical danger beyond the minor risk of bacterial infection that comes with any small puncture wound.
If you find a racer on your property and are not comfortable with its presence, the simplest approach is to leave it alone and it will move on. Racers have large home ranges and do not stay in one spot the way a ratsnake might linger around a barn with a mouse problem. Habitat modification can also discourage them: keeping grass short, removing brush piles, and sealing gaps under sheds reduces cover that attracts both racers and the small animals they eat. Killing the snake is both unnecessary and, in some states, potentially illegal, as Coluber constrictor has protected status in parts of its northern range where populations have declined.
For anyone who appreciates the natural pest-control services snakes provide, a racer is a particularly useful neighbor. Its diet hits rodents, insects, frogs, and other snakes, making it one of the more versatile predators in a suburban or rural ecosystem. The fact that it eats other snakes is just one line on a long résumé.