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How do snakes find food? When they find it, how do they
catch it? And once they catch it, how do they eat? Let's find out!
On the Hunt
When snakes are hungry, their hunting behavior is triggered usually
by the smell of prey. The speed at which a snake's tongue flicks in and out of its
mouth increases dramatically. Because snakes "taste smells", this allows the
snake to locate its prey more easily.
 Some snakes will actively pursue a prey item. Other snakes
employ the "sit-and-wait" method. Generally, a snake's hunting methods are
determined by the abundance or scarcity of prey.
Mice and other, larger prey (rats, rabbits, deer, etc.) are seldom
found in large numbers. So when a snake senses that food is nearby, the snake
will go searching for it. Snakes will then pursue their prey until there is a
good time to strike. This is when being extremely silent and having good
camouflage come into play. Prey can't hear the footsteps of a hunter that has
no feet!
Snakes that eat ants and other small insects often live very
close to an ant colony or termite mound. When these snakes need to eat, they
simply go to an area where there is a lot of insect traffic and catch the
insects as they pass by. Bat-eating snakes tend to live in bat caves. They wait
on a high ledge for when the bats fly in and out of the cave. The snakes then
catch the bats in mid-flight.
 Snakes native to desert areas are at a disadvantage. It is
often difficult to find a large population of prey items. Plus, with so few
plants or rocks to hide behind, it is very difficult for these snakes to stalk anything.
Instead, many desert snakes bury themselves in the sand and lay still. When a
prey item comes close enough, the snake strikes from under the sand - usually
with great success.
Some snakes prefer immobile prey. Often, egg-eating snakes
can find food easily. The sole concern of these snakes is to eat their meal
before the prey's parents return to the nest. (picture provided by wikipedia.org)
Ready to Strike
With the exception of egg-eating and some insectivorous
snakes, most snakes require the ability to quickly strike at and catch their
food. Once the snake determines that it is close enough to the prey item, it
curls into the "S" position and waits.
Snakes usually strike with the front 1/3 of their bodies.
The more of their bodies they use, the less accurate the strike is likely to
be. Snakes have to use a considerable amount of energy to propel themselves
forward. Consequently, a full-body strike may reduce their focus, or just make
it that much harder to maintain control of their bodies while in the air.
 A snake's strike happens very quickly. Some snakes can
strike more quickly than the reaction time of many animals, including humans.
This is a considerable feat, since a person's reaction time can be as fast as a
few hundredths of a second.
So what about animals that can react more quickly than a snake?
Generally, a snake wouldn't bother trying to hunt prey that is too fast;
however, scientists have found a snake that tricks its prey right into its
jaws!
Like many other snakes, the tentacled snake (Erpeton
tentaculatum) of Southeast Asia can strike in a few hundredths of a second. But
the fish this snakes likes to eat have reaction times of just a few thousandths
of a second. To overcome their significant disadvantage then, the tentacled snake
doesn't strike the fish. Rather, it makes use of the fish's natural reflex.
Fish are very sensitive to changes in pressure. They have
many sensory receptors on their sides that allow them to feel the movement of
the water as them swim. When a fish feels a sudden increase in pressure on one
side (indicating that something is coming towards the fish), it immediately turns
away from the oncoming pressure and swims away from the object.
When the tentacled water snake is on the hunt, it positions
itself in a "J" shape in the water; the snake's head sits opposite of its
midsection. When fish swim close by, the snake remains still until one swims
into the curve of the "J". As the fish swims between the snake's head and
midsection, the snake very quickly jerks its middle in the direction of the
fish. Because of the fish's natural reflex to swim away from the sudden
movement, it immediately swims straight into the snake's ready jaws.
Here is a high speed video taken by biologist
Kenneth Catania of the snake in action!
Next Time
Now that we've discussed how snakes find and catch their
food, we'll learn how they subdue and eat it.
Other Blog Entries
New Animal Attractions
Reptiles: A Scaly Introduction
Snakes: They're All Around
Snakes: A Family Affair (Part 1)
Snakes: A Family Affair (Part 2)
Snakes: Clever And Deadly Behaviors
Snakes: Do The Locomotion (Part 1)
Snakes: Do The Locomotion (Part 2)
Snakes: A Look Inside
Snakes: Feeling Sounds And Tasting Smells
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