Snakes are beautiful and, to most people, mysterious animals. And although there are thousands of snake species out there, telling them apart can prove a hard task. Knowing the difference between same-colored snake species is highly crucial, especially when dealing with snakes like the black racer, cottonmouth, and black rat.
The black racer, cottonmouth, and black rat snake are all black snakes that can be found in North America. Although they look similar at first glance, the main difference between them is that the cottonmouth is venomous, while the black rat snake and the black racer snake are non-venomous.
In this article, I’ll discuss the main differences between these three beautiful snakes. I’ll also explore some fun and interesting facts about them, making you better prepared for your walks in the wild.
The Main Differences Between the Black Racer Snake, Cottonmouth, and the Black Rat Snake
Although similar in appearance, the black racer snake, cottonmouth, and black rat come with tons of differences. Here is a table that will make it easier to differentiate between them in case you ever come across any of them:
| Name | Black racer snake (Coluber constrictor) | Cottonmouth (Agkistrodon piscivorus) | Black rat snake (Pantherophis obsoletus) |
| Habitat | All of the US Habitat generalists Prefer fields and edges of forests and wetlands | South of the US Wetlands, lakes and rivers Live mostly near freshwater but have also been found in brackish and saltwater habitats | Central North America Farmlands, hillsides and forests Also found on the borders of swamps and river floodplains |
| Size | 33 to 65 inches (84 to 165 cm) | 30 to 42 inches (76 to 107 cm) | 42 to 84 inches (107 to 213 cm) |
| Appearance | Smooth and slender Solid black or gray body Lighter underside, sometimes in a blue hue White collaboration under their heads | Heavy body Juveniles are brown with dark crossbands and yellow tail tips Adults are dark olive-brown to completely black, with dark crossbands Dark underside with brown-yellow patches White coloration inside the mouth | Slender body Juveniles are gray with black blotches Adults have shiny black scales Underside is light gray or brown White coloration under their head and on their neck |
| Venom | Non-venomous | Venomous pit vipers | Non-venomous, constrictor |
| Diet | Lizards, rodents, birds, eggs and other snakes | Birds, lizards, crayfish, turtles, fish, and other snakes | Main food source is rodents Also eats lizards, birds, eggs and frogs |
| Behavior | Daytime hunters | Opportunistic hunter. Hunts during the day and at night | Diurnal and nocturnal hunters, most active after sunset |
| Lifespan | 10 years | Less than 10 years | 10 to 15 years |
Let us look at the differences between the black racer snake, cottonmouth, and the black rat snake in more detail:
Habitat
Although all three of these snakes can be found in North America, they still prefer different habitats:
The Black Racer Snake
The black racer snake lives in North and Central America, from Guatemala all the way to Canada. They can be found anywhere from deserts to forests and farmlands but have also been seen in suburban environments.
Cottonmouth
These snakes are native to the Southeast US. Since they are semi-aquatic, they thrive in swampy areas. Cottonmouths can be found in marshes, lakes, and creeks. They prefer slow-moving water and a lot of vegetation that provides them with a great hiding place when hunting.
The Black Rat Snake
The black rat snakes can be found in the Eastern and Central US. They like forests and rocky hills but are also one of the most common snakes found in suburban habitats like farmhouses and yards.
Size and Appearance
The Black Racer Snake
The black racers are slender snakes that can grow from 2.7 to 5.4 feet (84 to 165 cm) and weigh 1.25 lb (560 g). Females are slightly smaller than males. They are completely black with 17 rows of slick scales that give them a matte look. Their underside is light, sometimes even bluish.
The black racer snake has a small head, not much wider than the rest of its body, with white coloration under the chin. The largest black racer snake ever recorded was 6.08 feet (185 cm)
Cottonmouth
Cottonmouths are heavy-bodied snakes with keeled scales that can grow from 2.5 to 3.5 feet (76 to 107 cm) and weigh from 3 to 4 lb (1.3 to 1.8 kg). Males are larger and heavier with larger heads.
When born, they are brown, with reddish-brown crossbands and a bright yellow tail tip they use to bait prey. The tail tips help in a process called caudal luring, which helps to lure prey.
As they continue to grow, cottonmouth snakes lose the bright tail tip and become more uniform in color – olive, black or dark brown with 13 dark crossbands.
Cottonmouths have large, triangle-shaped heads with dark bands next to the nostrils and white coloration inside of their mouths – this is also where they get their name from. Their underside is dark with brownish-yellow spots.
The largest cottonmouth ever recorded was found in the National Wildlife Refuge, the Great Dismal Swamp in Virginia, and measured 6.16 feet (188 cm) in length.
The Black Rat Snake
These slender-bodied snakes can grow from 3.5 to 7 feet (107 to 213 cm) and weigh 1.1 to 4.9 lb (0.5 to 2.2 kg). Males are larger than females. They have black, gleaming scales with a light gray and tan underside with a checkered pattern.
Juveniles are dark gray with 28 to 40 black blotches. They have white chins and necks and wedge-shaped heads resembling those of a turtle. The longest black rat snake ever recorded was 8.41 feet (256 cm) in length.
Venom
The Black Racer Snake
Black racer snakes are non-venomous and aren’t aggressive when they encounter humans. In spite of their scientific name (Coluber constrictor), they are not constrictors – when they catch their prey, they bite it and crush it by pinning it down with their body, then swallow it whole.
Cottonmouth
Cottonmouths are pit vipers with a venom potentially deadly to humans. Pit vipers are snakes that have heat-sensitive pits organs next to their nostrils that allow them to track the prey by their body heat, even in pitch-black conditions.
They are not aggressive in their encounters with humans and will try to run if they can. Most bites humans sustain are caused by mishandling or by accidentally stepping on a cottonmouth. Their venom causes local tissue death and prevents blood from clotting.
They kill their prey with a single bite and then coil around it until it stops fighting, then they swallow it whole.
The Black Rat Snake
The black rat snakes can bite when feeling threatened but are not venomous. They are not aggressive and run from humans if the circumstances allow it.
The black rat snakes are constrictors – they coil around their prey until they suffocate it with strong constrictions before swallowing it whole.
Diet
The Black Racer Snake
The black racer snake is a diurnal snake, meaning it hunts during the day. Juveniles eat frogs, insects, small rodents, and small snakes. Adults add small birds (and their eggs), mice, rats, and rabbits to their menu.
They are quite useful to have around farms because they serve as a kind of pest control.
Cottonmouth
Cottonmouths are opportunistic generalists meaning they feed on a wide range of animals, both alive and dead which is something very few snakes do. They are cathemeral, meaning they hunt both during the day and at night.
Their diet consists of turtles, crayfish, fish, and even juvenile alligators. Cottonmouths also eat mice, rats, lizards, insects, and dead animal carcasses.
The Black Rat Snake
The black rat snake is a diurnal and nocturnal hunter, meaning it is usually active after sundown. They eat frogs and lizards but get their name because of the fact they mostly eat mice and rats.
This makes them extremely useful and a welcome sight around farms since they keep the mice and rat numbers under control.
Fun and Interesting Facts About the Black Racer Snakes, Cottonmouths, and the Black Rat Snakes
The Black Racer Snake
- The black racer snake gets its name because of its swift movement – it can reach a top speed of between 8 and 10 miles per hour (13 and 16 kilometers per hour).
- By vibrating their tail in the grass, they create a buzzing noise that mimics the rattle of a rattlesnake.
- They are known to be great climbers, gliders, and swimmers.
- Although their scientific name is Coluber constrictor, they are not constrictors at all – they kill their prey by crushing it between their bodies and the ground.
- They are also known under the name the cow sucker because people would encounter them in the barn near the cows and think they were there to drink the milk. All the while, the black racer was there hunting mice and rats.
Cottonmouth
- Cottonmouths are also called water moccasins.
- They are excellent swimmers adept at hunting in water. Although they mostly live near freshwater, they have also been seen swimming in brackish and saltwater.
- They can attack their prey underwater.
- Cottonmouths are able to swim upstream.
- Although cottonmouths give birth to live juveniles, they actually carry their eggs – they incubate them for five months inside their body.
- Their venom consists of hemotoxins that break down blood, making it unable to clot and causing massive blood loss, internally and externally – blood can gush through all orifices.
- Baby cottonmouth snakes are equally as dangerous as adults – this is because they are born already fully venomous.
- They are one of the rare scavenger snakes – almost no snakes eat carrion in the wild. Cottonmouths also have cannibalistic tendencies meaning they will eat other cottonmouths if the opportunity arises.
The Black Rat Snake
- They are one of the largest snakes in North America.
- The black rat snakes are fantastic climbers and swimmers.
- They are also called pilot snakes. This is because they often brumate with other snakes like rattlesnakes and racer snakes – this has caused the incorrect belief that they lead other snakes to their brumation dens.
- When they feel threatened, they mimic rattlesnakes by coiling their body and shaking their tail quickly.
- They are great at camouflage. When approached, they stay motionless, their coloration allowing them to blend with the ground.
- Another common name they are known under is the chicken snake – this one they got because they can often be seen near chicken coops trying to snatch some eggs.
Conclusion
Identifying snakes is very important, especially in the case of these common beautiful black snakes. The reason for this is that one of them is poisonous, and the other two are not.
For people who spend a lot of time in nature and on farms, it is important to know how to react if they encounter one of them.
Now that you’ve read the article, you can go out on your next walk armed with the best weapon – facts!