Monday, August 18, 2014

Black Rat Snakes

I noticed some mouse activity around the stored bird seed in the garage, so I knew that the Black Rat Snakes had moved out of the house.  Like many predatory species, the Black Rat Snake breaks its home range into hunting parcels.  It will hunt in one parcel until the prey becomes scarce and then it will move into the next parcel.  By the time it has made the circuit through all of the parcels, the prey will have rebounded in the first parcel and hunting will again be good.  My garage and attic make up one parcel.

Black Rat Snakes become more uniformly dark as they age.  In good light though, you can still see a remnant of the handsome pattern worn by the snake as a youngster.

Snakes moving across a loose substrate cannot get the leverage they need for smooth gliding locomotion.  They must use their muscles in a different way to achieve something similar to a belly crawl.  This is their equivalent of a person crossing an icy parking lot.  I’ve heard people attribute this condition to snake arthritis, road accident, dog attack, vicious clubbing and many other imaginative afflictions, but it is really just a natural condition for the snake under certain circumstances.

I found this snake coming around the corner of my barn and noticed that it was in a perfect position for estimating its length.  This wall was built with standard concrete blocks which are 16 inches in length, including the space between blocks, when in place.  The front part of the snake stretches two and a half blocks or 40 inches.

Around the corner we find the tail end stretching about four fifths of a block or 13 inches.  Add on another inch to cover the portion that wraps around the corner and the snake totals 54 inches or four and a half feet.  An impressive specimen.

The snake proceeded along the wall and entered the barn by way of the small space beneath the large barn door.  As soon as it got inside, it began scaling the wall.  These snakes are excellent climbers and easily ascend what is practically a smooth vertical surface.

The shelf atop the barn wall is a preferred site for shedding old skin.  This is usually my first indication that the snakes have moved into the hunting parcel that includes the barn.

Here are three fresh sheds, all left within the past week.

I usually take the skins and hang them in a nearby tree.  With luck, there will still be some lengths of skin around next spring that are suitable to those birds that use this type of material in their nests.

While I was exiting the small barn door, this young snake was trying to enter.  Its juvenile pattern is clear to see.

The small snake showed signs of having recently fed.  I hope that bulge represents a small mammal and not one of the adult fence lizards.

The water tubs at the barn corners are frequently used by the snakes. 

I usually see the snakes scale the barn wall to access the water tub.  This one chose to employ the stepstool method.

Large quantities of water are often consumed at one time.  This one drank for almost a full minute.

The snakes sometimes soak in the tub and I thought this one was going to do just that.

Instead of soaking, it shot through the tub and out the other side so fast all I could catch was the tip of its tail disappearing over the back side.

It took off across the grass and entered the field beside the barn.  It’s fun to watch these snakes going about their business undisturbed. 


  1. How very cool! For some people, though, it would be a toss up whether the snakes or the mice are preferable. :)

  2. Hi, Lois. I've had guests who encountered snakes and others that encountered mice. From their reactions, I think the majority prefer the mice.

    Hi, Furry Gnome.

  3. This was an enjoyable and informative post, as usual, Steve. I particularly like the part about moving across loose substrate - it does look like something is wrong with it. Would you happen to know why snakes often sun themselves on the road in an undulating wave versus straight out?

  4. Thanks, Katie. I have noticed that snakes moving into a large open area, such as a road, large rock or bare ground, will just stop and bask in whatever position they happen to be in when their entire length becomes exposed to the sunlight. I haven’t observed enough basking snakes to give my impressions any scientific validation, but it seems that the snake feels the warmth and simply pauses. I guess being in such a position would allow the snake to make a quick escape should danger approach.