There are approximately
3,500 species of
snakes in the world. However only a small portion of them are venomous.
Snakes are found on all continents except
Snakes can be found in almost all habitats:
deserts, grasslands, forests, underground, rivers, even open oceans.
Snakes, like other reptiles, are ectotherms
("cold-blooded"). They rely on behavioral means, like basking or seeking
shade, to regulate their body temperature.
Snakes in temperate climates hibernate
through the colder months. Some species gather in huge communal dens,
sometimes even sharing them with other species. Rattlesnakes and garter
snakes are two North American species that gather in dens in large
numbers to hibernate.
Most snakes have only one functional lung,
the right. The left lung is vestigial or absent.
All snakes are carnivorous eating only
meat. This includes mammals, birds, insects, fish, invertebrates, eggs,
and other reptiles, including snakes.
There are three main ways snakes catch
their prey: "harmless" prey like earthworms, frogs, and fish are
swallowed alive. Many species grab their prey then constrict it.
Venomous snakes strike and inject venom in
their prey to kill it.
It is a myth that constriction is used to
crush prey. Constriction suffocates prey by squeezing a bit tighter
every time the animal exhales until the animal has no room left to
Some snakes are very specialized feeders
and have adaptations to help them eat their preferred food. The African
egg-eating snake eats eggs and has vertebrae with downward projecting
spines that opens the eggs. Kingsnakes eat other snakes including
venomous species. They have a high natural immunity to the venom of the
species that share their geographic range.
Snakes rely heavily on their sense of smell
to detect prey. Unlike humans, snakes use their tongue for smell. Their
tongue picks up airborne scent particles and places them in the
Jacobson's organ in the roof of the snakes' mouth. This scent organ then
can distinguish between different odors.
Snakes do not have external ears and cannot
hear like humans do. Their main "hearing" is the ability to pick up
vibrations from the ground in the bones of their skull and jaw.
Several species have special heat pits that
can detect differences in temperature of only a fraction of a degree.
This ability to detect heat is especially useful for snakes that eat
mainly warm-blooded prey.
Snakes do not chew their food, but swallow
Snakes need to shed their old skin as they
grow. The faster they are growing the more often snakes shed their
skins, sometimes once a month if growth is rapid. Snakes that are not
experiencing much growth or activity may only shed a few times a year.
Snakes never stop growing. They will grow
throughout their lives, but growth may be extremely slow in mature
The skin is normally shed in one piece. It
comes off inside out, starting at the head and peeling back as the snake
moves to help the shedding process along.
Snakes give birth in two ways. Some like
rat snakes, milk snakes, and kingsnakes lay eggs. Others keep the eggs
in their bodies until they hatch. The young are then born.
Garter snakes, copperheads, and
rattlesnakes are all examples of Indiana snakes that give birth.
Any snake, whether venomous or not, can
A venomous snake may release as much or as
little venom as it chooses, and may even give a "dry" bite with no venom
at all. Venom is not something a snake wants to waste.
In Indiana, there are four species of
venomous snakes: eastern massasauga, timber rattlesnake, western
cottonmouth, and the northern copperhead. The eastern massasauga's range
includes the northern part of the state while the others are restricted
to the southern part. The cottonmouth has only been confirmed in a few
spots in the extreme southern part of Indiana.
All the venomous snakes in Indiana are pit
vipers. They have a heat pit between the eye and nostril on each side of
the head. They also have vertical pupils.
The venom of juvenile snakes can be more
toxic, drop for drop, than that of the adults.
Many species of snakes live around water,
particularly water snakes, queen snakes, and garter snakes. Most
so-called "water moccasins" are nothing more than one of the species of
nonvenomous water snakes that live in Indiana.
Rattlesnakes give warning by rattling their
tail. Many other non-venomous snakes such as rat snakes and kingsnakes
also buzz their tail similarly as a warning to leave them alone.
As a last resort, the hognose snake (and
some other species) will lie on their backs and pretend to be dead when
Snakes can use their venom for defense as
well as to capture prey. The spitting cobra aims a stream of venom at
its attacker's eyes, temporarily blinding the victim.
Most snakes try to avoid a confrontation by
moving away. Keep in mind that snakes are easily outrun by people who
also wish to avoid meeting them.