Venomous Bites
Venomous Bites
Venomous snakes inject their venom by biting, as do spiders, centipedes, octopuses, and a few lizards and mammals. All of these animals use their venom to paralyze or kill their prey, as well as to defend against predators.
There are about 500 species of venomous snakes worldwide. Only a few are deadly to humans. Among them are cobras, which are found in parts of Africa and Asia.
Cobras prey on rodents, birds, frogs, lizards, snakes, and other small animals. A cobra kills prey with venom produced in glands at the back of its jaws, near its eyes. The venom flows down grooves in the fangs at the front of its mouth.
The biggest cobra, the king cobra, is also the world’s largest venomous snake. The largest king cobra ever measured was 18 feet (5.6 m) long. However, the king cobra, like other venomous snakes, is not eager to use its venom in self-defense. It is more likely to flee or hide, even though its venom is strong enough to kill an elephant with just one bite. If a predator approaches the cobra or its nest, the cobra raises the front of its body off the ground and hisses. It also spreads the ribs of its neck, creating a hood out around its head. If these warnings are ignored, the snake strikes.
Some cobras spray venom at predators instead of biting them. These “spitting cobras” have openings midway down their front fangs. The snake squeezes venom through these openings. The spray can hit a target up to 10 feet (3 m) away. It usually ends up in the predator’s eyes, causing terrible pain and blindness. Sometimes, the blindness is permanent.
Rattlesnakes, like cobras, deliver their venom with fangs. However, a rattlesnake’s fangs are not fixed in place like a cobra’s. instead, they are hinged. They fold back in the rattlesnake’s mouth when it is closed. When the snake opens its mouth to strike, the fangs spring out, ready for action.
A rattlesnake’s colors and patterns help camouflage it. If it is spotted by a predator, the rattlesnake will try to slither away from danger. Yet, if a predator bothers it, the rattlesnake coils up and rattles its hollow, scaly tail sections.
Another venomous North American snake, the cottonmouth or water moccasin, sends a warning by stretching open its whitelined mouth. The world’s deadliest snake, the black mamba of Africa, also warns away enemies by opening its black-lined mouth. A recently discovered species of venomous snake in Asia is able to change colors. This behavior has earned it the name “chameleon snake.” Scientists think the color changes may be a warning to predators.
Some kinds of snakes, such as coral snakes, are clad in warning colors that advertise their venomous nature. Coral snakes are ringed with bands of black, red, and either white or yellow. These relatives of cobras live in North, Central, and South America, where they prey mainly on lizards and other snakes.
Unlike snakes, the world’s two species of venomous lizards use their venom mainly for self-defense, not hunting. The Mexican beaded lizard and its smaller cousin, the Gila (pronounced “heela”) monster, are both slow-moving animals that feed mainly on eggs, baby rodents, and baby birds found in nests on the ground. If disturbed, these lizards bite with their strong jaws. Venom flows through the teeth from glands in their lower jaws. The lizards chew their victims so the venom sinks inside them. Both species have bright warning colors: They are black, with yellow or pink uneven bands.
Vivid warning colors also adorn venomous centipedes, such as the giant Sonoran centipede. This many-legged animal, which lives in some of the same desert lands as the Gila monster, can grow to be 8 inches (20 cm) long and is boldly patterned in orange and black. It bites insects, worms, frogs, and other prey with a pair of sharp, claw-like fangs near its head. Muscles squeeze venom out of a gland in each fang. Like snakes, centipedes use venom for defense as well as hunting.
Spiders’ venom also does double duty. Many spiders catch their prey in webs, then deliver a killing bite with their fangs. Hunting spiders lie in wait for their prey, or prowl about in search of prey and then pounce on it like a tiger. They hang on to their prey with their legs while they bite it, killing it with venom.
Spiders also bite predators that attack them. Most spiders’ fangs are not strong enough to pierce predators’ skin, though, and the venom is not strong enough to harm. A few spiders do have powerful venom. The black widow spider’s venom is more potent than many snakes’ venom. The brown recluse spider has venom strong enough to make a person feel ill for several days. Like all spiders, however, these species would rather hide from danger than bite someone.
Octopuses also would rather hide, but they will bite if they are stepped on or attacked. An octopus uses its venom and its strong, sharp beak to kill crabs, fish, and other prey. Most octopus venom is not strong enough to do great harm to humans, but the venom of blue-ringed octopuses can kill.
Different species of blue-ringed octopuses live in parts of the indian Ocean and the western Pacific Ocean. Normally, they wear camouflaging colors of brown, gray, and pale yellow. But if they are disturbed, bright blue rings suddenly appear. These rings are warning colors—and the warning is not a bluff.
A greater blue-ringed octopus makes one kind of venom for hunting and another kind for self-defense. This little octopus, which is no bigger than a golf ball, contains enough venom to kill about 25 people in just a few minutes. Most people harmed by a blue-ringed octopus have either picked it up or stepped on it.
The ocean contains another group of animals that are among the world’s most venomous animals: the cone snails. There are about 600 species of cone snail. Most are found in tropical waters and on coral reefs. Only a small number contain venom that is deadly to humans.
Cone snails use their venom to kill prey, such as worms, snails, and fish. The venom is delivered by a bite that works much like a sting or harpoon. The snail shoots out a tube attached to a sharp, hollow tooth. Venom flows from a gland in the snail through this tube and into the prey. The snail uses its venom in self-defense when it is attacked by a hungry fish.
Venomous snakes inject their venom by biting, as do spiders, centipedes, octopuses, and a few lizards and mammals. All of these animals use their venom to paralyze or kill their prey, as well as to defend against predators.
 |
| This juvenile king cobra is giving off a warning sign by hissing. |
There are about 500 species of venomous snakes worldwide. Only a few are deadly to humans. Among them are cobras, which are found in parts of Africa and Asia.
Cobras prey on rodents, birds, frogs, lizards, snakes, and other small animals. A cobra kills prey with venom produced in glands at the back of its jaws, near its eyes. The venom flows down grooves in the fangs at the front of its mouth.
The biggest cobra, the king cobra, is also the world’s largest venomous snake. The largest king cobra ever measured was 18 feet (5.6 m) long. However, the king cobra, like other venomous snakes, is not eager to use its venom in self-defense. It is more likely to flee or hide, even though its venom is strong enough to kill an elephant with just one bite. If a predator approaches the cobra or its nest, the cobra raises the front of its body off the ground and hisses. It also spreads the ribs of its neck, creating a hood out around its head. If these warnings are ignored, the snake strikes.
Some cobras spray venom at predators instead of biting them. These “spitting cobras” have openings midway down their front fangs. The snake squeezes venom through these openings. The spray can hit a target up to 10 feet (3 m) away. It usually ends up in the predator’s eyes, causing terrible pain and blindness. Sometimes, the blindness is permanent.
Rattlesnakes, like cobras, deliver their venom with fangs. However, a rattlesnake’s fangs are not fixed in place like a cobra’s. instead, they are hinged. They fold back in the rattlesnake’s mouth when it is closed. When the snake opens its mouth to strike, the fangs spring out, ready for action.
A rattlesnake’s colors and patterns help camouflage it. If it is spotted by a predator, the rattlesnake will try to slither away from danger. Yet, if a predator bothers it, the rattlesnake coils up and rattles its hollow, scaly tail sections.
Another venomous North American snake, the cottonmouth or water moccasin, sends a warning by stretching open its whitelined mouth. The world’s deadliest snake, the black mamba of Africa, also warns away enemies by opening its black-lined mouth. A recently discovered species of venomous snake in Asia is able to change colors. This behavior has earned it the name “chameleon snake.” Scientists think the color changes may be a warning to predators.
Some kinds of snakes, such as coral snakes, are clad in warning colors that advertise their venomous nature. Coral snakes are ringed with bands of black, red, and either white or yellow. These relatives of cobras live in North, Central, and South America, where they prey mainly on lizards and other snakes.
Unlike snakes, the world’s two species of venomous lizards use their venom mainly for self-defense, not hunting. The Mexican beaded lizard and its smaller cousin, the Gila (pronounced “heela”) monster, are both slow-moving animals that feed mainly on eggs, baby rodents, and baby birds found in nests on the ground. If disturbed, these lizards bite with their strong jaws. Venom flows through the teeth from glands in their lower jaws. The lizards chew their victims so the venom sinks inside them. Both species have bright warning colors: They are black, with yellow or pink uneven bands.
Vivid warning colors also adorn venomous centipedes, such as the giant Sonoran centipede. This many-legged animal, which lives in some of the same desert lands as the Gila monster, can grow to be 8 inches (20 cm) long and is boldly patterned in orange and black. It bites insects, worms, frogs, and other prey with a pair of sharp, claw-like fangs near its head. Muscles squeeze venom out of a gland in each fang. Like snakes, centipedes use venom for defense as well as hunting.
Spiders’ venom also does double duty. Many spiders catch their prey in webs, then deliver a killing bite with their fangs. Hunting spiders lie in wait for their prey, or prowl about in search of prey and then pounce on it like a tiger. They hang on to their prey with their legs while they bite it, killing it with venom.
Spiders also bite predators that attack them. Most spiders’ fangs are not strong enough to pierce predators’ skin, though, and the venom is not strong enough to harm. A few spiders do have powerful venom. The black widow spider’s venom is more potent than many snakes’ venom. The brown recluse spider has venom strong enough to make a person feel ill for several days. Like all spiders, however, these species would rather hide from danger than bite someone.
Octopuses also would rather hide, but they will bite if they are stepped on or attacked. An octopus uses its venom and its strong, sharp beak to kill crabs, fish, and other prey. Most octopus venom is not strong enough to do great harm to humans, but the venom of blue-ringed octopuses can kill.
Different species of blue-ringed octopuses live in parts of the indian Ocean and the western Pacific Ocean. Normally, they wear camouflaging colors of brown, gray, and pale yellow. But if they are disturbed, bright blue rings suddenly appear. These rings are warning colors—and the warning is not a bluff.
A greater blue-ringed octopus makes one kind of venom for hunting and another kind for self-defense. This little octopus, which is no bigger than a golf ball, contains enough venom to kill about 25 people in just a few minutes. Most people harmed by a blue-ringed octopus have either picked it up or stepped on it.
The ocean contains another group of animals that are among the world’s most venomous animals: the cone snails. There are about 600 species of cone snail. Most are found in tropical waters and on coral reefs. Only a small number contain venom that is deadly to humans.
Cone snails use their venom to kill prey, such as worms, snails, and fish. The venom is delivered by a bite that works much like a sting or harpoon. The snail shoots out a tube attached to a sharp, hollow tooth. Venom flows from a gland in the snail through this tube and into the prey. The snail uses its venom in self-defense when it is attacked by a hungry fish.
Support our developers
