What You Should Know About Rat Snakes in Louisiana
Rat snakes are attractively marked, non-poisonous constrictors which eat, primarily, rats and mice and some birds and eggs. They are known for their excellent climbing ability and their great length which can be up to 101 inches.
In the south rat snakes are often called "chicken snakes" because they are usually found around barn yards and have been known to eat eggs and chicks.
5 Important Questions About Rat Snakes
- How do scientists categorize rat snakes?
- How do I identify a Louisiana rat snake?
- What habitat do rat snakes prefer?
- How do rat snakes reproduce?
- How do rat snakes hunt?
This article will go into detail about each of these issues and teach you the pros and cons of having rat snakes around. In fact, rat snakes do a great service for humans as rodent control agents. Let's learn more about them!
How Do Scientists Categorize Rat Snakes?
Rat snakes are medium-to-large, nonvenomous snakes that kill by constriction. They pose no threat to humans. There are Old World (Eastern Hemisphere) and New World (Western Hemisphere) rat snakes, and the two types are fairly different genetically.
In the past two decades, the question of what is a rat snake has become increasingly complicated to answer. Until the early 2000s, both Old and New World rat snakes were generally thought to belong to the same genus, Elaphe. Recent work with Taxonomy places the New World Rat Snakes in the genus Pantherophis, rather than Elaphe. Genetic studies also indicate that the current species E. obsolete may be composed of three distinct species.
The Three Species of E. obsolete Could Be
- The eastern rat snake (E. alleghaniensis)
- The Texas rat snake (E. obsolete)
- The gray rat snake (E. spiloides)
In Louisiana there are two subspecies: the Black Rat Snake (Elaphe o. obsolete) of the North and Central areas and the Texas Rat Snake (E. O. lindheimeri) of the south.
Common Names for Rat Snakes include:
- Chicken snake (which is what we used to call this very long snake),
- Oak snake
- Goose snake.
- Corn snake, Elaphe guttata guttata
- Great Plains rat snake, Elaphe guttata emoryi
- Adult black rat snake, Elaphe obsoleta obsoleta
- Juvenile black rat snake, Elaphe obsoleta
- Adult Texas rat snake, Elaphe obsoleta lindheimeri
How Do I Identify a Louisiana Rat Snake?
Rat snakes are very long (up to 101 inches). The Black Rat Snake (Elaphe o. obsolete) is common in North and Central Louisiana. When trying to identify a Louisiana Rat Snake there are several things to keep in mind.
Characteristics of a Louisiana Rat Snake
- Uniformly black dorsum or, at least, a dark background that contrasts very little with the blotches.
- Their patterns can have large dark blotches on a gray-brown or yellowish brown, belly mottled, or checkered background.
- Rat Snakes show more regional variation in body pattern and color than any other North American Snake. Some are very colorful and quite attractive.
What Habitat Do Rat Snakes Prefer?
Rat snake habitats are widely varied. They live all across the country and that includes many locations in Louisiana. Rat snakes like fields and briar patches, but they are not confined to them. Where you find a rat snake depends on several factors, including the age of the snake.
Where Do Rat Snakes Live in Louisiana?
- In the northern part of the state they occur on roads and in swamps, wooded areas, pastures, briar patches, cultivated fields, open sandy places, houses and barns.
- In southern Louisiana specimens were found near barns and houses, in trees and bushes and near swamps and bayous.
- Rat snakes are constrictors and their prey includes small mammals, birds and bird eggs, which they either swallow whole or break inside the throat by squeezing it with their vertebrae.
- Young rat snakes feed mostly on tree frogs, small lizards and baby rodents. This means that they can be in the brush and by the water.
How Do Rat Snakes Reproduce?
Rat snakes are oviparous, meaning they lay eggs that spend little to no time incubating. Rat snakes will lay a clutch of 6 to 44 eggs (but usually about 15 eggs) in stump holes, tree holes or other dark, moist places. Rat snakes reproduce sexually and competition to mate is high.
Facts about Rat Snake Reproduction
- Several females may nest together.
- Rat snakes have been know to return to the same area year after year.
- The eggs hatch about 2 months after laying.
- If conditions are right, females may lay two clutches of eggs per year. Otherwise, they usually just lay one.
How Do Rat Snakes Hunt?
Hunting and diet. Rat snakes are constrictors. They squeeze their prey to death and swallow it whole. The baby and young snakes may eat cold-blooded animals. They’ll eventually adapt to a diet where they eat only warm-blooded prey. The rat snake is known to wait and ambush its prey. The rat snake hides away in the brush and stages an ambush. Snakes will also actively forage for their prey and will pounce when the opportune moment arrives. The rat snake will go and eat all of its kill in one sitting.
The Rat Snake's Prey
- Mice, rats, chipmunks, voles, and other rodents
- Frogs, lizards, and other reptiles
- Birds and bird eggs
A Real-Life Interaction with a Rat Snake: The Pileated Woodpecker and the Rat Snake
The pine and hardwood mixed forest in which we live is prime habitat for Texas Rat Snakes so we have many interactions with them. One of the most interesting occurred one weekend, not long after we bought our place. I was working to clear one of the areas in the garden of invasive imported plants and vines, when I noticed a Pileated Woodpecker acting strangely about 40 feet up in a Loblolly Pine tree.
The bird was giving it's jungle call and pecking on the side of the tree. Then it would fly down a few feet and repeat the process. After it moved down about 15 feet, I was able to see the Rat Snake. The Woodpecker was herding the snake down the tree.
As the pair got closer, I found a long stick and waited at the bottom of the tree. When the snake was in reach, I placed the stick near it so that it could crawl onto it. It worked like a charm and in minutes I had the snake in my hands. I placed it in an empty aquarium with a lid (that once housed hamsters) and waited until my husband got home.
It was a beautiful snake, but since we had erected many bluebird nest boxes in the area where it was found, we decided to relocate it to the riparian area down by the Tchefuncte River where there would be plenty of small mammals for it to eat.