Spraying, Spitting, and Spewing
Oozing, leaking, bubbling, and dripping toxic and irritating fluids
can repel many predators. Some animals go one step further.
Instead of letting predators get close enough to touch them, they
keep them at bay by spraying, spitting, or otherwise spewing fluids
at them.
Skunks are the most famous animals to use this tactic. A
skunk has musk glands under its tail that can spray a terriblesmelling
fl uid at predators. Its white stripes are warning colors
that are easily seen at night, when the skunk is active. An experienced
predator knows to avoid it.
An inexperienced predator, however, gets a warning. Each
species has its own way of saying “back off.” A hooded skunk
stamps its feet, then turns around to raise its tail and spray. A
striped skunk also stamps and raises its tail, then curves sideways
to aim its musk glands whilekeeping an eye on its foe. The spotted
skunk stamps its front feet, then stands on them in a handstand
and twists its back so that its musk glands are aimed at the
predator.
Failure to heed these warnings earns the predator a blast
in the face from the skunk’s musk glands. A skunk can shoot its
smelly spray 13 feet (4 m) and hit its target. The spray not only smells bad, but also irritates the predator’s nose, mouth, and eyes.
It can even temporarily blind the predator. After spraying, the
skunk toddles off, leaving its victim pawing at its face.
Some snakes, such as the grass snake of Europe, have glands
that release terrible-smelling fluid from their hind ends when
they are caught. The green woodhoopoe, an African bird, pokes
its tail out of its nest holeand sprays a smelly fluid from a gland
at its base. The fluid, which smells worse than rotten eggs, repels
predators such as snakes and rats. Other birds use droppings to
repel enemies. A duck called the eider, for example, spews strongsmelling
droppings on its eggs just before it flees from its nest if
frightened by a predator.
Many kinds of beetles spray repulsive fluids from their hind
ends, too. The darkling beetle of the southwestern United States
reacts to a predator by practically standing on its head. Then it
sprays fluid from the end of its abdomen. The spray repels ants,
birds, lizards, and some rodents. A ground beetle of the southeastern
United States sprays acid at ants that attack it. Carrion
beetles, which feed on animal carcasses, also spray smelly, irritating
fluid at ants, spiders, and other predators.
Many species of ants spray, too. Carpenter ants, for example,
do not have stingers. Instead, they bite enemies with their jaws
and then spray acid from their hind ends into the wounds. This
acid is also used to kill the insects they eat.
The champion tail-tip sprayers among insects are bombardier
beetles, found nearly worldwide. A bombardier beetlestores the different chemicals that make up its spray in different
parts of its abdomen. If the beetleis attacked, it empties the
chemicals stored in one part of its abdomen into the chamber
that holds the rest of the brew. They combine to form an explosive,
hot fluid that bursts out of the beetle’s hind end with a
loud pop.
A bombardier beetlecan twist its abdomen to aim in nearly
any direction. It can even shoot over its back. The hot, irritating
spray repels ants, birds, and frogs.
Another insect, a walkingstick insect called the devil’s rider,
also uses a “cannon” to spray a terrible smelling fluid. Its defensive
glands are located behind its head. Scientists who study this
insect report that its spray irritates their lungs as well as their
eyes. Like the bombardier, the devil’s rider can spray in almost
any direction. Unlike the bombardier, it does not wait for a bird
to attack before defending itself. It sprays when the bird is still
about 8 inches (20 cm) away.
Insects also use their mouths to shoot fluids at predators.
Grasshoppers, for example, are known for their ability
to spit. This “spit” is really the grasshopper’s stomach contents.
It is often mixed with poisonous substances from a part
of the insect’s throat called the crop. The lubber grasshopper
of the southeastern United States, which is clad in warning
colors of black and yellow, not only spits a dark-brown stream
at predators, but also hisses at them and bubbles with irritating
foam.
The larvae of insects called sawflies also spit up their stomach
contents at predators. The larvae feed on eucalyptus trees
in Australia, which contain an oil that stops most insects from
eating its leaves. The oil is stored in a special pouch in a larva’s
body. If an ant, mouse, or bird attacks, the larva spits up the
thick, strong-smelling goo. The larvae of some species that feed
in groups will cluster together in a circle, with their heads facing
out. Then the wholegroup spits up together.
Even some birds cough up stomach contents on predators.
Many seabirds that nest on the ground, such as albatrosses, throw
up their oily, fishy meals when a predator approaches. This defense
behavior often is used by chicks. Birds or mammals that get hit will carry the terrible smell with them for days. They also
may be chilly: Feathers and fur soaked with the fishy oil will do
a poor job of keeping an animal warm in the cold places where
many seabirds nest. Scientists who study these birds wear waterproof
clothing when they are at work.
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