A-Nature Blog

This snakeskin “decorated” the ceiling fan in the Past’s kitchen. It probably came from a Texas Rat Snake that may have been searching for birds’ nests. Al Past photo.

12/08/2017 – Surprise Find in the Ceiling Fan (Karen L. P. Benson)

High ceilings, thick stucco walls, and ceiling fans help south Texans stay cool during our warm summers and even during our not-so-cold winters.  We take those fans for granted, rarely noticing them.  However, recently, Al Past looked up at his kitchen ceiling and saw a curious decoration dangling from the blades of the fan.  It seemed to be a whitish, almost transparent, ribbon.  At least that is what Al thought…for a moment.

Then it hit him…It was a snakeskin!  You can imagine his train of thought:  Oh, a snakeskin.  Uh, oh…It was above my head the whole time and I never knew it!  And finally…Oh, no!  If that is just the skin, where is the snake?

After checking every other ceiling fan and fixture, cabinet and shelf, corner and crevice, and never seeing a live snake, Al was able to breathe a sigh of relief.  But he kept wondering:  what if it was a poisonous snake?  And what if it comes back?

Uneasy with his find and these lingering questions, Al showed me his photo of the shed snakeskin.  Seeking to reassure him that it was probably not a poisonous snake, I began to wonder if it was possible to identify a snake from its shed skin alone.

Turns out you can!  A website called Steemit.com has posted a step-by-step procedure for identifying a snake’s species from its cast-off skin.  The original post was by a snake biologist called HerpetologyGuy.  He understands that a homeowner might feel a bit squeamish, or even panicked, by the sight of a snake skin inside one’s home.  He reassuringly states “Snake skins may seem a little gross, but you can think of them as gifts: they are like little clues to the snake’s identity and can save you the trouble of being surprised by a snake or getting too close to one trying to identify it.”

This snakeskin, although missing a small portion, was over three feet long. Karen Benson photo.

With this in mind, I collected the shed skin from the Past’s ceiling fan.  Actually, I let Al unwind the skin and pull out parts of it from inside the motor of the fan.  It must have wiggled around in there quite a bit trying to squirm out of its too-tight skin!  Imagine trying to take off a snug wetsuit if you had no arms or legs.  You’d probably start by rubbing your cheek against something rough to get the head piece off first. This is exactly what a snake does, too.  Once your head is free, you contort yourself, wiggling and rubbing until the rest of the suit peels off, inside out.  You probably have to stretch and pull and maybe even tear the suit to get your body free.  So does the snake.  Once it is out, the snake takes off, leaving the inside-out shed “suit” behind.

To determine what kind of snake left its shed, you look first at the overall length of the skin.  Because the skin once covered both the top and bottom of each scale, the discarded shed, with subsequent stretching, can appear to be almost twice as long as the original snake.  But the length gives you your first clue:  the size of the snake.  I measured the skin that Al had obtained:  It was just over three feet long.  In life, it was probably a bit over two feet long.  Now, not all species of snakes can get that long.  With this first step, I eliminated Western Worm Snake, Rough Earth Snake and other little (foot-long or less) snakes.

Next, I looked at the girth.  This snake had been about four inches around at its middle.  In general, non-venomous snakes are long and thin, while venomous ones are stout and thick-bodied.  This snake looked like he had been pretty stout.  I decided not to mention this observation to Al.

The third step was to look at the tail.  If it seemed to have come off with an intact tip, like a sock, then it was NOT a rattlesnake.  Rattlesnakes do not shed the end of their tail, leaving the “button” to dry out and form the rattle.  Unfortunately, my specimen seemed to be missing most of the tail.

However, I had the head end of the skin.  The scales and eye coverings were distinct.  I could see there were two pre-frontal scales near the nostrils and there were no pits between the eyes and nostrils.  Not a rattlesnake nor any type of poisonous pit-viper.  Thank goodness!

The head of the snake emerges from the mouth end of the skin, turning the snakeskin inside out. You can see the scales that covered the eyes on the side of the head. Karen Benson photo.

Still I wanted to figure out what kind of snake ventured into a home, somehow climbed the walls, and decided to shed on a ceiling fixture.  So, using Alan Tennant’s Guide to Texas Snakes (1998) I followed the Key to Identification.  I was thinking this fairly large, pretty stout, climbing snake might be a Texas Indigo Snake.  I like indigo snakes.

But it was not to be.  When I got to the mid-body scale rows on the dorsal side of the snakeskin, I began counting from the side diagonally forward to the top, then backward diagonally to the other side.  I got 27 scales.  That seemed like a lot.  I recounted.  It was still 27.  It could not be an indigo snake; they only have 17 rows of scales across their middles.

Following the Key, I learned that 27 rows of scales meant that the snake had belonged to a genus of rat snakes.  This shed skin had come from a Texas Rat Snake, or maybe a Great Plains Rat Snake (both Elaphe species).  Texas Rat Snakes are mostly arboreal, climbing trees to raid birds’ nests, but they don’t hesitate to take a rodent if one crosses their path.  The Great Plains Rat Snakes prefer canyons, caves, and cellars, and although they are agile climbers (taking young birds, bats, and rodents), they prefer to rest in subsurface lairs.

Rat snakes are harmless, even beneficial in that they keep the rodent population under control.  Accept their little gifts of shed skins as proof that they have been there, but have now moved on.  Hopefully, those “little gifts” won’t be in your ceiling fan!

Column by Karen L. P. Benson