REPTILES OF THE METRO AREA
METROPOLITAN  NATURALIST
_________________________________________________________________________________________________________
Black Rat Snake (Elaphe obsoleta)

This is a very common snake in our area. The black rat snake starts life as a gray and brown snake,
seen in the pictures at the bottom of this page. As the snake matures the back turns almost all black,
although some remnants of the young snake's pattern can still be seen even in a large adult. These
snakes can grow over 6 feet long. These non-venomous snakes are constrictors, squeezing their
prey to suffocate it before eating it. Their prey is mostly rodents - mice, rats and even young
squirrels - and birds. Occasionally these snakes get into birds nests and eat young birds or eggs,
sometimes being a pest by invading nesting boxes. This snake is sometimes called the Eastern Rat
Snake (
Elaphe alleghaniensis or Pantherophis alleghaniensis)
Black Rat Snakes are excellent climbers and are often seen high up in trees, sometimes stretched across a
branch sunning themselves as in the picture below.

I often find Black Rat Snakes sunning on logs or rocks or even on black top roads. They are slow moving and
easily approached or caught. They are also sometimes found crawling through the woods or across hiking trails.
They can also be found under boards, logs, or sheet metal, particularly when the snake's eyes are cloudy as the
snake prepares to shed it's skin.  I once watched a Black Rat Snake at Liberty Reservoir as he crawled into a
hollow log and ate a litter of young White-Footed Mice in a nest inside the log. The snake appeared to follow the
scent, possibly of the parent mice traveling to and from the nest, to the young mice. After cleaning the nest of
young mice, the snake proceeded to climb a large tree and disappeared into the forest canopy.

There are two "Black Snakes" in our area. The Black Rat Snake and the
Black Racer. The two are easily
distinguished by their behavior as well as their appearance. The Rat Snakes are relatively slow moving and are
often seen sunning themselves on branches or logs, while black racers are usually very active, fast moving, and
rarely lay out in open to sun themselves. The underside of the adult Rat Snake fades from almost all black near
the tail to a checkerboard pattern to almost all white under the chin. The scales of the rat snakes are keeled,
while the Black Racer has smooth scales.
black rat snake
black rat snake
black rat snake
black rat snake
Black Rat Snakes can climb up and
down the trunks of trees.
black rat snake - juvenile
black rat snake - juvenile
Juvenile Black Rat Snake. This snake
was found inside a rotting log in
Owings Mills, Maryland.
I have found that many snakes, and other animals as well, can be observed in the same place day after day, even year after
year. Snakes will often bask in the same spot or rest in the same crevasse where they can be observed for a summer or even
several summers in a row. A very patient observer might even be able to watch from a distance as they move to and from their
roost and as they hunt for food, watch their behavior change through the molting cycle, and get some insight into the daily life
and behavior of these fascinating creatures. Since snakes are cold blooded and have a slow metabolism, they do not need to
eat constantly like birds or mammals. Snakes are often content to stay in one place for long periods, so it can take a lot of
time to see any activity. Catching a snake even one time will often cause it to move and find a new location, so by catching a
snake you might lose the opportunity to observe the animal in the future and the animal might have to look for a new home,
basking site, or hunting spot.
The greatest threat to snakes and most other wildlife is habitat destruction. In the past, killing of snakes by
misinformed people was a big problem. Today many people tolerate snakes, even enjoy seeing them or catching
them alive.  As the number of collectors and wildlife enthusiasts increases and the amount of habitat decreases, well
meaning collectors and wildlife lovers may be the second greatest threat to our native reptiles and amphibians. It has
become more and more important for us to be conscious of our impact on wildlife, and to minimize our impact by
watching from a respectful distance when possible. Handling, disturbing, and capturing wildlife should be avoided or
done responsibly if you feel you must get a close inspection.
Many Black Rat Snakes are relatively calm and reluctant to bite when captured and others bite violently when captured.

Black Rat Snakes tend to tame quickly and can be kept in captivity and fed a diet of mice or small rats. Although wild
black rat snakes usually tame easily, I urge you to buy a captive bred snake from a reputable breeder rather than taking
them from the wild if you would like to keep one as a pet. A reputable breeder can give instructions on proper care and
maintenance as well as reducing the pressure of collectors on wild populations.

Although these snakes are common in the Baltimore-Washington area, habitat destruction is reducing the available
habitat for them. Additional pressure on wild populations may come from pesticides and other chemical contamination.
Research suggests that reptiles, amphibians, fish, and other wildlife are affected by estrogenic, carcinogenic, and
teratogenic effects of chemicals that are being released in increasing amounts into their environment.
Black squares on a white belly near
the snake's head merge into an all
black belly at the tail end of the adult
Black Rat Snake.