Discover the Largest Rat Snake Ever Recorded

A closeup of a Baird's rat snake's head
© Rusty Dodson/

Written by Emmanuel Kingsley

Updated: April 11, 2023

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Rat snakes are harmless colubrid snakes. They are widespread and live in a variety of habitats. Despite their lack of harmful venom, these snakes have hidden cards up their sleeves. Rat snakes are known to rattle their tails to imitate or mimic venomous rattlesnakes. There are over 50 known species of rat snakes. These snakes aren’t short. On average, they measure anywhere from 4 to 6 feet but some specimens have been known to exceed this. Discover the largest rat snake ever recorded in this article.

Rat Snakes

common snakes in georgia

Rat snakes are mildly venomous colubrid snakes.

©Gabbie Berry/

Just like kingsnakes, vine snakes, and milk snakes, rat snakes are mildly venomous colubrids. These snakes, however, do not use their venom to kill or capture prey. They kill their prey through constriction and are known to feed on small mammals and rodents. Rat snakes use their venomous saliva to aid in swallowing and digesting their dead prey.

How Long Do Rat Snakes Get?

Japanese Rat Snake is known for climbing high into trees and taking baby birds out of their nests.

On average, rat snakes measure anywhere from four to six feet. However, several species exceed this length.


On average, rat snakes measure anywhere from four to six feet. However, several species exceed this length. At birth, they measure about 13 inches. With proper feeding, a baby rat snake can attain five feet in four years.

What is the Largest Rat Snake Ever Recorded?

The largest rat snake ever recorded was a 13-foot and 1-inch-keeled rat snake.


In 2015, Indraneil Das, a conservation biologist at Universiti Malaysia Sarawak published his book “Field Guide to the Reptiles of South-East Asia”. In it, he documented a keeled rat snake specimen that measured 13 feet and 1 inch.

Keeled Rat Snake 

Keeled rat snakes (Ptyas carinata) are the longest rat snake species. They measure anywhere from 4 feet to 9 feet. This species is known for its big eyes and dark colors. They are either black or deep gray.  Often they have a distinctive checkered pattern.

Smallest Rat Snake Species

Mexican rat snakes are the smallest rat snake species.


Mexican rat snakes (Pseudelaphe flavirufa) are native species of Central America and Mexico. They are also called yellow-red rat snakes and have three recognized subspecies. Mexican rat snakes are the smallest rat snake species. They are about 12 to 14 inches long as adults. This is just a little over 1 foot long.

How to Identify A Rat Snake

If you’re on the lookout for a rat snake, you need to know how to identify them. Rat snakes have keeled and ridged scales. They are either black or deep brown and have white chins. Various species have definitive features mixed with their black or dark bodies. Yellow rat snakes, for example, have black and greenish-yellow stripes.

Do Rat Snakes Make Good Pets?

Rat snakes have calm, docile, and shy personalities. They aren’t quick to attack and can become quite used to being handled in captivity. They aren’t frequent feeders. Western rat snakes, for example, eat as infrequently as once a month. Due to these reasons, rat snakes make good pets. They are the most popular pet snake species. If you’re considering a pet snake, it is a good idea to go for smaller species so space wouldn’t be a problem. Remember to purchase your pets from the pet store and not attempt to domesticate a wild rat snake.

Where are Rat Snakes Found?

Rat snakes are a widespread species. They are found in most eastern and midwestern states. However, it is easier to spot them in southeastern American states. Rat snakes can be found in every southeastern state.

Will a Rat Snake Bite You?

Rat snakes can bite. Even though they do not bite often, it is important to remember that they can and might if they feel threatened.

What To Do If You Get Bitten By A Rat Snake

Although rat snakes aren’t venomous, bites from them should still be treated as emergencies. If a rat snake’s toxic or venomous saliva should get into the wounds made by its fangs, you could be in for a couple of days of pain. If you get bitten by a rat snake, contact emergency services immediately.

How Do Rat Snakes Defend Themselves and Hunt For Food?

Rat snakes defend themselves and hunt with various abilities they possess. They hunt primarily by stalking and constricting their prey. They also have musk which they sometimes mix with feces and spray to deter predators. Apart from being extremely stinky, musk odor is notoriously hard to get rid of. As we mentioned before, they also rattle their tails to imitate venomous rattlesnakes

Rat Snakes and Global Warming

Rat snakes are a unique species for many reasons but one reason is extremely intriguing. As global warming begins to make changes to the climate, experts predict that many amphibians and reptiles will not be able to adapt as fast as temperatures are changing. However, warmer climates might actually benefit rat snakes.

Global warming will cause temperatures to rise during both day and night times as the ozone layer gets thinner. This will allow rat snakes to hunt at night since the weather will be tolerable for them. Rat snakes currently hunt during the day because the weather is warm enough for them to be fully active. However, the daytime is also when hawks are active. Hawks are rat snakes’ major predators. They have such a high success rate because rat snakes are active during the day.

If temperatures go higher, rat snakes will hunt at night when hawks are asleep. This also means that they will become nocturnal. This, in turn, will translate to higher hunting success. Rat snakes will be able to hunt larger animals such as birds that sleep and cannot see clearly at night. They will be less alert and less capable of detecting and protecting themselves from rat snakes. 

Global warming will tilt the battle in the favor of rat snakes a bit. They will feed better, become bigger, and be able to protect their eggs and themselves better. However, as you can imagine, what global warming gives, global warming takes. Eastern rat snakes will not be so lucky. Due to the warmer climate, they could wake on a sunny day in February or March instead of waking from hibernation in April or May.

The ecosystem, this way, is meticulously balanced, so this early emergence could spell doom for the species. They could be exposed to fatal conditions that they would not have had to face if they were hibernating. Also, since global warming will result in unpredictable temperature fluctuations, these rat snakes could very much freeze to death!

Other Record-Breaking Snakes

Rat snakes are common, backyard snakes that grow surprisingly large and keep rodents in check. Now that you’ve learned about them – you might want to read about another common snake that loves to eat rodents – the gopher snake. Gopher snakes look a lot like rattlesnakes – and they certainly take advantage of it by building their whole defense system around their deceiving appearance.

Gopher snakes take the impersonation one step further by pretending to be a rattlesnake – rattle and all. They shake the ends of their tails against the ground and emit a rattling sound that doesn’t come from their tails but from their throats. These rattlesnake mimics have developed a unique epiglottis (the flap over the larynx that keeps food out of the windpipe) that enables them to sound just like a rattle.

They raise up like rattlesnakes and hiss and rattle – but a bite from a gopher snake would be painful but not deadly. They are non-venomous constrictors that don’t even have fangs. They could damage a vein and cause severe bleeding – so don’t tempt them! Even if you identify these snakes and breathe a sigh of relief – they are still large, highly aggressive snakes that can inflict a painful injury.

One of the most prevalent snake varieties in the Western Hemisphere, gopher snakes, also called bullsnakes, can be found in Mexico, Western Canada, and the Western United States. These large, thick-bodied snakes thrive in densely wooded areas, prairies, and deserts and have been known to hunt in parks and suburban neighborhoods. So, just how long is the largest gopher snake ever recorded? It’s over eight feet! Read the next article to find out exactly how big these snakes can get – and learn more about the incredible rattlesnake imposter – the gopher snake.

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