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Students can watch this helpful video about camouflage to help them do their activities and learn more about camouflage as a defense mechanism.

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Students can watch this helpful video about mimicry to help them finish their activities and learn about mimicry as a defense mechanism.

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Students will watch this BrainPOP video about the defense mechanism of camouflage to learn about one of the major defenses some prey use.

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Learn about camouflage, the protective coloring that allows animals to survive by blending into the background.

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Students will use this article to obtain/research information about animals that use defense mechanisms.

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Defense mechanisms are very important to all animal life. Animals in every biome must eat to survive. With predators being high on the food chain and always on the lookout for a meal, prey must constantly avoid being eaten. Adaptations that prey employ add to the chances of survival for the species. Some of these adaptations include defense mechanisms that can give prey an advantage against their enemies.

Types of Defense Mechanisms

There are several ways animals avoid falling prey to a predator. One way is very direct and comes naturally. Imagine you are a rabbit and you have just noticed a fox preparing to attack. What would be your initial response? Right, you'd run. Animals can use speed as a very effective means of escaping predators. Remember, you can't eat what you can't catch!

Camouflage
Another defense mechanism is camouflage or protective coloration. One form, cryptic coloration, allows the animal to blend in with its environment and to mask its identity. Cryptic coloration is important to the survival of many new-born and young animals, as it is often their main defense against being detected by predators. Some animals blend in so well with their environment that it is very difficult to identify them. For example, some insects and other animals can look like leaves; both in their visual appearance and their behavior.

It is important to note that predators also use cryptic coloration to avoid detection by unsuspecting prey.

Playing Dead
When faced with danger, some animals pretend to be dead. This type of adaption is known as thanatosis. Opossums and snakes can even emit a fluid that produces a foul smell, thus adding to the pretense.

Such behavior tricks predators into thinking that the animal is dead. Since most predators avoid dead or rotting animals, this type of defense mechanism is often very effective.

Trickery
Trickery can also be used as a formidable defense. False features that appear to be enormous eyes or appendages can serve to dissuade potential predators. Mimicking an animal that is dangerous to a predator is another effective means of avoiding being eaten. For example, some harmless snakes have bright warning colors that resemble the colors of dangerous venomous snakes. Warning calls can also be used by one animal species to trick another animal species. The African fork-tailed drongo bird has been known to mimic meerkat warning calls when meerkats are eating their prey. The alarm causes the meerkats to flee, leaving their abandoned meal for the drongo to finish.

Physical Features
Physical anatomical structures can also serve as a type of defense mechanism. Some animals' physical features make them very undesirable meals. Porcupines, for example, make a very difficult meal for predators because of their extremely sharp quills. Similarly, predators would have a tough time trying to get to a turtle through its protective shell.

Chemical Features
Chemical features can be just as effective at deterring predators. We all know the hazards of scaring a skunk! The chemicals released result in a not so pleasant aroma that an attacker will never forget. The dart frog also uses chemicals (poisons secreted from its skin) to deter attackers. Any animals that eat these small frogs are likely to get very sick or die.

Warning Calls
Some animals sound the alarm when danger approaches. For example, oxpeckers (birds that live in mutualistic relationships with grazing animals) will give a loud warning call when predators get too close. African elephants emit a rumbling alarm call when they hear the sound of African bees. Animals can also give distinctive calls to identify the type of threat. For instance, monkeys have one alarm sound for leopards and a different sound for eagles.

Predator-Prey Relationship

To sum it all up, the predator-prey relationship is important to maintaining balance among different animal species. Adaptations that are beneficial to prey, such as chemical and physical defenses, ensure that the species will survive. At the same time, predators must undergo certain adaptive changes to make finding and capturing prey less difficult.

Without predators, certain species of prey would drive other species to extinction through competition. Without prey, there would be no predators. The animal organisms in such an environment could become endangered or even extinct. The predator-prey relationship ensures that the cycle of nutrients in bomes continues. Thus, this relationship is vital to the existence of life as we know it.

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Defense mechanisms are very important to all animal life. Animals in every biome must eat to survive. With predators being high on the food chain and always on the lookout for a meal, prey must constantly avoid being eaten. Adaptations that prey employ add to the chances of survival for the species.

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Students will use this article to obtain/research information about animals that use defense mechanisms.

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Roughly one in five mammal species is a bat. You may have heard of the famous vampire bats that feed on blood, but some lesser-known species use sonar to catch fish, scurry across the ground like mice, build their own tents, and even stick to sheer walls with suction cups. Let's get face to face with some of the most bizarre bats in the world.

1. Some bats can stick to vertical walls.

If you want to attach something to a smooth vertical surface-a car window, maybe, or a slippery shower wall-you might use a suction cup. Disk-winged bats use them, too. They have special cups on their ankles and wrists that help them stick to smooth tropical leaves. This gives them a high, safe place to rest in the bustling tropical forest. Sucker-footed bats, meanwhile, hang on using wet adhesion-they ooze a liquid that helps them cling to a surface.

2. Some bats can catch fish.

When bats hunt insects at night, they find their prey with an amazing sonar-like ability called echolocation-they make sounds that bounce off objects, then listen to the echoes for clues about what's ahead. But the greater bulldog bat, which is named for its dog-like face, uses this sonar to catch fish. Flying above the water, it senses telltale ripples caused by the underwater movements of its prey. It skims the surface with its large feet and swiftly snatches a slippery meal.

3. One species of bat weighs less than a penny.

Kitti's hog-nosed bat is the world's smallest bat-and, in fact, it's in the running for the world's smallest mammal. This animal is just a little over an inch (33 millimeters) long and weighs less than a penny. It's also unique: its ancestors split off from other bats more than 40 million years ago. Kitti's hog-nosed bat is native to Burma and Thailand, where it's vulnerable to habitat destruction.

4. A few bats construct tents.

If you take a backwoods survival class, you'll learn to build a shelter out of the natural material around you. And if you're like most beginners, your first few shelters might fall down or let in too much rain. Shelter-building is a hard skill to master-but some bats have got it down. They gnaw the veins of a large tropical leaf, making it fold into a tent that protects them from rainfall and predators. One of these tent-making species is the Honduran white bat. A group of these animals snuggling under their tent looks like a pile of marshmallows.

5. Other bats crawl around on the ground.

When a New Zealand lesser short-tailed bat is hungry, it hits the ground. It folds its wings up tight and uses them as forelegs as it scurries, mouse-like, across the forest floor in search of a snack. This bat's diet is very diverse-it will eat nectar, pollen, berries, insects, and more.

6. Bats come in amazing patterns.

Bats aren't just brown. The painted woolly bat of Southeast Asia is orange and black like a jack-o'-lantern. Indonesia's stripe-faced fruit bat is also ready for Halloween with some spooky makeup. Then there's the stunning pied bat; an inhabitant of central and western Africa, it has striking white blotches that make it look like a badger or a panda. These are just a few of the world's many, many beautifully patterned bats.

7. The stylish bat has amazing hair (and ears).

Native to sub-Saharan Africa, Chapin's free-tailed bat has a wicked hairstyle. Females sport a small tuft of fur that sticks up, but males have much larger crests that play a role in their courtship, and also just look cool.

8. Some bats sing love songs.

Move over, nightingales. The males of several bat species woo their mates with tunes that are every bit as complex as those of songbirds. For instance, to construct a proper song, a Brazilian free-tailed bat needs to follow certain rules and patterns, but like a great improvisational musician, he also adds his own special style that marks him as unique.

How do bats learn these complicated songs? They pick them up from their parents. The greater sac-winged bat of Central and South America hones its singing skills as a baby. Like human kids, young sac-winged bats babble as they try to copy their dads' sounds.

9. This bat has a horse's head.

Bats have some truly bizarre faces, but one of the all-time weirdest belongs to the male hammer-headed fruit bat of equatorial Africa. Females of this species have a relatively ordinary foxlike head. But males have heads that are almost three times as large as a female's. Their faces look even weirder from the front. Why that giant face and protruding lips? They help this bat make a unique honking call.

10. Some bats eat scorpions.

The desert long-eared bat chows down on scorpions-and doesn't mind being stung in the face as it pounces on its prey. Native to parts of Africa, the Middle East, and Asia, this bat catches scorpions by attacking their heads. The scorpions vigorously defend themselves by stinging the bat on its face and body. Unperturbed, the bat dispatches its meals and carries them back to a roost. There, it gulps down every bit of a scorpion-even the stinger.

The desert long-eared bat isn't fussy about which scorpion species it hunts. It'll even chow down on the deathstalker, one of the few scorpions in the world whose sting is potentially deadly to humans.

11. Many bats pollinate flowers.

Bees are famous for pollinating crops, and they help us grow such familiar foods as apples, pumpkins, and macadamia nuts. But bats are pollinators, too. Those huge Saguaro cacti of the U.S. Southwest, for example, bloom in the evening to attract pollinating bats. And the agaves that give us tequila are also bat-pollinated; they make stinky flowers on tall stalks that open at night. Wild bananas rely on bats, too.

12. One bat's tongue is longer than its body.

The tube-lipped nectar bat 's tongue is 1.5 times the length of its body. This bat uses its monstrous tongue to reach tasty nectar that's deep inside long-tubed flowers. When the tongue's not in use, it's stored in the bat's chest, next to its heart.

13. Some bats are freakin' huge.

Certain fruit-eating bats have a wingspan of over 5 feet. One of the largest is the golden-capped fruit bat of the Philippines. Named for its shock of blond "hair," it can weigh more than 2.5 pounds. It roosts in large numbers and dines on fruit such as figs. Deforestation and hunting, however, have put serious pressure on this batty behemoth.

14. Moths can jam a bat's sonar.

Many insect-eating bats use echolocation to hunt down their flying prey. But some moths fight back. They rub their genitals together to make sounds that interfere with a bat's sonar. Confused, the hungry bats zero in on the wrong location and bite at empty air.

This acoustic warfare isn't just limited to bats vs. moths. Researchers have found that Mexican free-tailed bats seem to jam each other's signals when they're competing for prey.

15. This bat's face doesn't even look like a face.

We've established that bats have weird faces. Some bats have yellow tube-shaped nostrils. Some look like their faces collapsed inward. Some are mostly made of ears. But let's end this list with one of the most extraordinary-looking species. Bourret's horseshoe bat, which lives in Southeast Asia, has a face that suggests an origami project gone wrong. Why the long nose? It's perfectly shaped to help focus the bat's sonar.

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Roughly one in five mammal species is a bat. You may have heard of the famous vampire bats that feed on blood, but some lesser-known species use sonar to catch fish, scurry across the ground like mice, build their own tents, and even stick to sheer walls with suction cups.

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Students will use this article to obtain/research information about animals that use defense mechanisms.

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We are all aware of the fight or flight principle in biology, where an animal responds to a threat by facing the enemy or fleeing from it. There are some fascinating ways that nature deals with these threats. This list will show the ten animals (plus a bonus entry) with the weirdest defense mechanisms.

There are many creatures with the power of flight but this feature is generally not attributed to fish. Flying fish are able to jump out of the water and fly or glide for long distances. This is used as a defense mechanism to escape from predators.

The flying fish has a streamlined, torpedo-shaped body which helps it gain enough energy to break through the surface of the water. To get out of the water, the fish swims at speeds of up to 37 miles (60 km) per hour. The fish's pectoral fins have evolved into large wings which allows the fish to become airborne. Once it is out of the water, it can fly for up to 656 feet (200 meters), using its tail fin as a sort of propeller. In 2008 in Japan, a flying fish was observed gliding for a record 45 seconds.

The Hagfish is an ancient organism that has existed for 300 million years and is the only animal with a skull and no vertebrae. When disturbed, it expels a disgusting, slimy substance at predators. As it mixes with water, the slime expands and there can be up to 5 gallons (20 liters) produced. This creates a distraction as the attacker tries to get out of the mess. It also creates a knot in its body and this, along with the slime, allows the Hagfish to escape the clutches of a predator. The slime can choke fish as it accumulates in the gills. The Hagfish has been known to slime sharks as shown in the video above. Skip to 1.30 minutes in for the best reaction.

The tiny threads that make up the Hagfish's slime are ten times stronger than nylon and this is of great interest scientists, who believe it can be used to make clothes.

The Potato beetle has developed a strange way to avoid being eaten by larger insects. The larvae cover themselves in their own feces. The dung is poisonous and the foul smell wards off predators.

The beetle eats from the nightshade plant and it reuses the toxic substances produced by this in its feces. This defense is called a fecal shield. Feces is guided onto the beetles' backs through a series of muscle contractions in the abdomen and over time, it forms the shield.

When it detects a significant threat, the Boxer crab will pack a powerful punch using sea anemones attached to its claws. They look like pom-poms, but they can be deadly to other sea creatures and they have a strong sting. The crab waves his claws around when disturbed, to ward off danger.

There is a mutual agreement with the two organisms as they both benefit from the arrangement. The boxer crab gains an awesome defense mechanism that would put most other animals to shame, and the anemone becomes mobile and is able to obtain more food. The crab also uses sponges and corals in place of the anemone.

Similar to the Potato beetle, the Eurasian roller's offspring will cover themselves in their own body fluid to avoid becoming food for a hungry animal. This time however, it is vomit that forms the shield. The vomit-covered baby birds look and smell horrible so they are less likely to be eaten. The parents will smell the vomit too and they quickly fly back to the nest to ward off the threat, which is usually a bird of prey or snake. This is the only bird observed to use vomit as a form of communication.

Nature's most disgusting defense mechanism is that of the sea cucumber. Once disturbed, it will eject its sticky intestines and other organs out of the anus, at the attacker; entangling it. This dazzles and distracts the enemy. In some species, the intestines are poisonous, containing a toxic chemical called holothurin. The sea cucumber's body contracts violently to squeeze out the insides.

The creature doesn't seem to mind this process, and the organs are restored quickly. It takes about six weeks for the missing body parts to be regenerated.

When the Turkey vulture is approached by a hungry predator, it will regurgitate the entire contents of its stomach. This is used as either an offering of food or to make the predators flee. The vomit of the vulture is utterly disgusting, and the smell completely puts off most predators. The vulture can then run away at a quicker pace as it is a lot lighter. Although, by this point, a lot of predators would have gone already. Some starving animals will actually resort to eating the vomit, even though it is very acidic and can burn. [http://vulturesociety.homestead.com/TVFacts.html]

This octopus is found in the oceans at depths of 1,900-3,200 feet (600-1000 meters). The Japetella heathi octopus has had to adapt to evade two types of deadly predators-those that hunt by looking for silhouettes created by the lighter waters above, and those which use their own light from bioluminescence. To avoid creating a silhouette, the octopus is almost completely transparent, except from its eyes and guts. However, these have become reflective, reducing their shadow. This allows light to pass through the creature, reducing its visibility to predators.

However, this is a disadvantage against predators with bioluminescence, such as the angler fish, as the octopus would reflect the light, allowing the fish to easily locate it. To avoid becoming food for the angler fish, when the octopus detects their light, it activates skin pigments. These pigments allow the octopus to change its color to red in less than a second, greatly reducing its reflectivity. This effectively makes the octopus invisible to angler fish and other headlight fish. When the threat is gone, and the light is no longer present, Japetella heathi reverts to transparency.

In a previous list, we featured a frog that can break its bones through its skin. However, the Iberian ribbed newt takes this to a whole other level. This creature is found on the Iberian Peninsula and Morocco. When under threat, the newt will push its ribs through the skin, out of tubercles on the side of its body. These ribs act as weapons to ward off attackers. Despite the rupturing of skin, the process causes no pain to the newt.

In order to do this, it moves its ribs away from the spine, increasing their angle by up to fifty degrees. The skin is stretched and the bones rip through. At the same time, a poisonous substance is secreted through pores on the skin. The spiky ribs puncture the attacker's skin and then the poison enters. This can even cause death. The newt's defense proves to be very effective.

Although the Iberian ribbed newt is unaffected by its defense mechanism, the same cannot be said about the Malaysian exploding ant. The ant defends the colony from attackers by blowing itself up. Two large glands full of a poisonous chemical are located all across the ant's body and when attacked, it will violently contract its muscles. This causes the fluid-filled glands to burst, releasing the sticky, poisonous substance from the head at the target. This substance not only entangles the attackers, but also causes extreme irritation and corrosion. This restrains the creature and can kill.

This frog has the ability to come back to life after being completely frozen with no brain or heart activity. This strange adaptation acts as a defense against the extreme cold.

During winter, when its core temperature drops too far below the regulatory limit, the wood frog's brain instructs its liver to produce huge amounts of glucose which acts as a sort of antifreeze. This prevents ice crystals becoming too large, therefore stopping cells and blood vessels becoming ruptured.

The frog can remain in this frozen state for weeks on end until a change in temperature allows it to thaw. The heart muscles, which have been protected by a huge build-up of glucose, suddenly burst into life by rubbing together. This generates an electric charge and gives the heart a burst of energy which allows it to start pumping again. The blood then starts flowing throughout the frog's body and after a few minutes, it is back to normal. This incredible adaptation allows the frog to survive in extreme environments such as northern Canada and Alaska.

Caleb is a listverse writer and moderator from Cornwall, UK. You can follow him on twitter

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10 Strangest Defense Mechanisms In Nature

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We are all aware of the fight or flight principle in biology, where an animal responds to a threat by facing the enemy or fleeing from it. There are some fascinating ways that nature deals with these threats.

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Students will choose an animal to be and talk about where it lives and its defense mechanism and even predator. Students may also write about some fun facts about the animal that they choose.

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Students will write a story/essay pretending to be an animal and a time when it got scared and had to use its defense mechanism.

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Students will work in groups to research 3 animals and their defense mechanisms. Students will put this information onto a poster.