11 of the Greatest Defense Mechanisms in Nature

Desperate times call for desperate countermeasures, and these animals understand this very well.
Christopher McFadden
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Nature, at first glance, may appear to be a tranquil and peaceful place — but there is also another side to it, which has been described as "red in tooth and claw". In reality, the natural world is a brutal dance of life and death. In response, many animals and plants have developed interesting and surprising defense mechanisms to defend themselves from their predators and, in some cases, the elements.

Let's take a look at some of the most interesting and extreme types of defensive mechanisms in nature. 

What are nature's defense mechanisms?

For the purposes of this article, we will define a defense mechanism, with regards to nature, as a strategy, or physical adaption, for protecting an organism against danger — like predation or environmental pressures. Not to be confused with the same term used in psychology.

The ways in which animals, and plants, keep themselves alive are widespread and, frankly, fascinating. Here are 11 great examples.

These range from the absurd to disgusting. Given the diversity found in nature, as you can appreciate, the following are far from exhaustive and are in no particular order.

1. The wood frog creates its own antifreeze to survive being frozen

natures defense mechanisms wood frog
Source: Travis/Flickr

Species: The wood frog

Their greatest defense mechanism: Using natural anti-freeze to survive being frozen alive.

During the height of winter, these frogs are able to survive the harsh climate by allowing their bodies to become largely frozen. Their hearts and brains are also put into a form of stasis with no activity. 

They perform this incredible feat in part by pumping their body tissues with large amounts of glucose, which acts as a form of natural anti-freeze to limit the formation of ice crystals which would otherwise burst their cells open.

2. The sea cucumber fires its internal organs at attackers

11 of the Greatest Defense Mechanisms in Nature
Source: Brocken Inaglory/Wikimedia Commons

Species: The sea cucumber

Their greatest defense mechanism: Ejecting its own intestines and other organs at the enemy to entangle and deter them.

The sea cucumber has an interesting, if seemingly disgusting, hostile defense mechanism. When threatened, it can eject its own sticky intestines and other organs out of its anus. This entangles the would-be predator. The organs can also contain a poison called holothurin. 

This ejection of organs is not fatal, but it takes the sea cucumber around 6 weeks to fully regenerate any lost organs.

3. The boxer crab uses sea anemones as boxing gloves

11 of the Greatest Defense Mechanisms in Nature
Source: Prilfish/Wikimedia Commons

Species: Boxer crab (Lybia tessellata)

Their greatest defense mechanism: Using sea anemones as boxing gloves to ward off predators. Sea anemones are surrounded by dangerous tentacles which are covered in stinging cells.

By entering into a mutually beneficial relationship, boxer crabs allow anemones to get a free ride on their claws. 

In return, the crab gets to use them as poisonous "boxing" gloves — pretty neat. 

4. The cuttlefish changes its color and shape to hide in plain sight

natures defense mechanisms cuttlefish
Source: Greg Hirson/Flickr

Species: The cuttlefish

Their greatest defense mechanism: Camouflaging its skin to blend into its surroundings.

Another common defense mechanism in nature is to simply hide, rather than fight.

This is where the cuttlefish, one of nature's great copycats and camouflage experts, excels. They are able to rapidly change their skin color and their body shapes to blend into their surroundings or to distract would-be predators.

5. These explosive ants defend their colony at the cost of their own lives

11 of the Greatest Defense Mechanisms in Nature
Source: Noel Tawatao/Wikimedia Commons

Species: Malaysian (Exploding) Ant

Their greatest defense mechanism: Although the name is a bit of a giveaway, these ants self-destruct to defend the colony when attacked. 

These ants might have one of nature's greatest hostile defense mechanisms. 

Soldier Malaysian ants have two large poison glands that the ant employs to incapacitate invaders and defend the colony. It does this by violently flexing so that its abdomen splits open and that causes the fluid-filled glands to burst and spray the enemy with the sticky poisonous substance. 

This also ends the soldier ants life, but can seriously hamper or even kill the attacker(s).

6. The slow loris can coat itself in poison

11 of the Greatest Defense Mechanisms in Nature
Source: Silke Hahn/Wikimedia Commons

Species: The Pygmy Slow Loris

Their greatest defense mechanism: Rubbing itself, and its teeth, in a poisonous substance secreted from glands on their arms. For some predators, this poison can cause anaphylactic shock.

Normally a very slow-moving creature, the loris is rather vulnerable to predators. To counteract this, it has poisonous glands on its arms that it rubs on its fur or licks to make the teeth poisonous in order to defend itself. More amazing still, the toxin is only activated when mixed with the loris's saliva in a natural chemical reaction. This makes it the only known venomous primate.

7. The porcupine carries Its own phalanx

11 of the Greatest Defense Mechanisms in Nature
Source: Hohum/Wikimedia Commons

Species: The Porcupine

Their greatest defense mechanism: Using its quills to counter-attack potential predators.

The porcupine uses a timeless strategy in nature — that attack is the best form of defense. It does this by raising its very long quills and charging backward or sideways at attackers. They can also stand their ground in defense situations, much like the phalanxes of old. 

One of the most impressive types of defensive mechanism, it can also suddenly stop and let the predator pursuing it run headlong into them. This causes the quills to detach and they can embed themselves in the predator.

This is very painful, and the quills are hard to dislodge.

8. The bombardier beetle is a natural WMD

Source: elderkpope/Flickr

Species: The Bombardier Beetle

Their greatest defense mechanism: Squirting a noxious concoction of chemicals that, when mixed, form an explosive reaction of hot fluid.

The bombardier beetle is able to spray its enemies with a hot, noxious spray of body fluids from its anus. This is a mixture of hydroquinones, hydrogen peroxide, and a mix of enzymes.

9. The Texas horned lizard literally cries blood

11 of the Greatest Defense Mechanisms in Nature
Source: Gregory "Slobirdr" Smith/Wikimedia Commons

Species: Texas Horned Lizard

Their greatest defense mechanism: Squirting pressurized blood from its eyes.

When threatened, the Texas horned lizard is able to squirt its own pressurized blood at any potential attacker. This is, however, the last resort for when its camouflage and physical spiked defenses fail.

10. The Iberian ribbed newt shape-shifts to defend itself

11 of the Greatest Defense Mechanisms in Nature
Source: David Perez/Wikimedia Commons

Species: Iberian Ribbed Newt

Their greatest defense mechanism: Using their own ribs to form poisonous spikes.

When attacked, this newt is able to push its ribs outside of its skin to form spikes that help to defend itself. It does this by moving them away from the spine and increasing their angle by 15 degrees. 

Its skin then stretches and the ribs penetrate through 'warts' along its sides and, simultaneously, a poisonous substance is secreted onto them through pores in the skin. The best part is that this appears to be a painless and survivable strategy. 

11. The hagfish knocks out predator fish's gills in defense

natures defenses hagfish
Source: Mike/Flickr

Species: The Hagfish

Their greatest defense mechanism: Expelling a slimy substance that can clog up the gills of attackers.

Hagfish are one of the oldest living fossils on the planet. They have existed for at least 300 million years and have an interesting, but disgusting, slimy substance that they can expel when attacked.

This substance, once it mixes with water, expands and can clog up, and choke enemy fish's gills. 

And that, ladies and gentlemen, is your lot for today. 

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