Rat Snake

Rat snakes are some of the most frequently seen snakes in the US, but they still cause a lot of confusion and panic. They’re often mistaken for whatever venomous snake lives in the same area. They’re relatively large snakes, and they have an intimidating defensive posture, raising the fronts of their bodies above the ground. And they can have a slightly triangular head if you’re looking at it and thinking, is that triangular? I don’t know… maybe? Kinda. Better assume it’s venomous.

It’s not venomous. Rat snakes are harmless, unless you’re small enough for them to swallow. They can even be beneficial to humans, keeping the rodent population under control. On the other hand, they’re notorious for stealing chicken eggs, which they can swallow whole. And they can clear out an entire nest of baby birds. (If you put up birdhouses, it’s a good idea to add predator guards.)

They’re also skilled tree-climbers*. If you live in the United States, and you see a snake hanging out in a tree in your yard, or from the rafters in a barn, or perched calmly on top of your doorframe as you go to open the door, chances are pretty good that you have a rat snake.

Identifying them can get a little complicated. They come in different patterns and colors, depending on the region. In peninsular Florida, they’re yellow with dark stripes:

Elsewhere on the Gulf Coast, they’re gray or tan with darker patches, like the one pictured at the top of this post.  And farther north, they’re black:

And to the west, you get this splotchy, stripey kind:

These are all the same species! At the edges of their regions, intergrade patterns are often found. The Atlantic coast has some olive-green ones, a mix of yellow and black. In the Piedmont, where I live, they’re mostly black but often have some faint markings.

Rat snakes are constrictors, like boas and pythons, but much smaller. A truly giant rat snake is about 7 feet long, and most adults are under 5 feet. Still, you could say they’re the closest thing the US has to pythons (except in the Everglades, where the Burmese python has become a pest).

They like abandoned buildings and other structures near humans, where the rats are plentiful. So if you see a big yellow, black, or brown snake hanging out in a tree or a hayloft, no need to panic. It’s probably just a rat snake going about its exterminator duties. Leave it alone, and enjoy fewer rats around your house.

• How does a limbless animal climb a tree? By using its belly scales to push against the rough bark.

Here’s a rat snake in action:

** Source for images (except the first one): Encyclopedia of Life