It can sometimes (often) be confusing as to what species of snake you’re looking at when you come across one on a trek along your favorite hiking trail, your backyard, or here at the Museum. I’ve often stated on this blog the clear difference between copperheads and other non-venomous snakes here at the Museum. But there are two species which even confuse me at times.
The black rat snake and black racer are both common snakes here at the Museum. As you may have guessed, both are black. The rat snake averages about five feet in length and the racer about four, but there’s a lot of overlap.
Both snakes climb trees and crawl along the grass and forest floor looking for prey. And, as I’ve already said, it can be confusing as to which one you’re looking at when you come across either. But, I’m going to tell you how to distinguish the two from one another. And, I’m going to show you pictures to back up some of what I’m going to tell you. By the time you get to the bottom of this page you should have little trouble identifying either snake.
After black rat snakes mature and lose their black and grey, highly patterned juvenile coloration (another story), they become mostly black. I say mostly, because their undersides, or their bellies, are white, or splotched white and black. The white extends from their “lips,” chin, and throat, right on down the belly to the tail. The white is not always visible when the snakes are crawling around in the leaf litter or grass, but you usually get at least a glimpse of white. Remember, the white is sometimes splotched with black or grey.
Racers are black overall, except for the chin. Some have white on the throat but that seems to be more common the further south you go, like Florida.
The rat snake’s head has rounded edges. The iris is usually light enough to make out the round, black pupil. And, to my eye, they seem to wear a perpetual skeletal grin accentuated by the presence of black between the white scales on the “lips.” They are wide-eyed, and always grinning.
Racers have more angular heads than do rat snakes. They have a rather blunt, squared off nose. And, there’s not even a hint of a grin. Their facial expression is a serious one. The iris is dark and often does not stand out against the pupil.
In cross section, rat snakes are loaf-of-bread shaped, whereas racers are round. But this may be difficult to determine as the snake crawls along.
While rat snakes can move quickly when they want or need to, they typically slither along at a slow and steady pace or sit quite still, waiting for prey to move. Racers often move along quickly and purposefully while seeking out prey under leaves, pine needles, behind objects, poking their noses into every crevice along the way.
Rat snakes have keeled scales. There are ridges running down the center of each scale, at least on the dorsal surface. Racers do not have these keels and so are smooth scaled.
And finally, one last direct comparison of both species’ heads.
Racers often poke their heads up out of the grass to “see what’s coming” (as in photo above) when about to cross a path, or simply to have a look around. It’s typical behavior.
One more thing, while both snakes would rather not have dealings with you, racers are more likely to stand their ground, sometimes shake their tail like a rattler, or even come at you when they feel threatened. Of course, they are non-venomous so no worries there.
So, the next time you see either of these snakes, whether here at the Museum or off in the wild somewhere else, you should now be better armed to make an informed identification of what your looking at.