7 Impressive Animal Defense Mechanisms

NOAA Photo Library, Flickr // CC BY 2.0
NOAA Photo Library, Flickr // CC BY 2.0

The deep-sea squid known as Octopoteuthis deletron has a startling defense mechanism: When threatened, the squid attacks its predator and then pulls away, breaking off the tip of its own arm and leaving it behind as a diversion. As the arm continues to glow and twitch, the squid makes its escape.

But this squid isn't the only creature with a bizarre tactic for keeping itself alive. Here are several other animals with impressive defense mechanisms.

1. THE LIZARD THAT SHOOTS BLOOD FROM ITS EYES

The Texas Horned Lizard is a scary-looking creature. Brown, plump and perfectly camouflaged in its native sandy environment, its first line of defense is its spiky demeanor. If the sharp spikes and horns don't ward off predators, the lizard steps it up a notch and squirts a well-aimed stream of blood out of its eyes. The stream of blood, which can go as far as 5 feet, is mixed with a foul-tasting chemical that wards off predators. But this odd weapon comes at a cost: The lizard may release one-third of its total blood supply this way, amounting to 2 percent of its body mass. Unfortunately, its population numbers are dropping thanks to a threat that won't retreat after a well-aimed squirt: habitat loss due to rapid urbanization in the Lone Star State. 

2. THE HAIRY FROG THAT BREAKS ITS OWN BONES

Emőke Dénes, Wikimedia Commons // CC BY-SA 4.0

What if every time you felt threatened, your first and only method of defense was to break your own bones and use them for weapons? Meet the hairy frog, a Central African species. When breeding, the male frogs develop thin strands of skin along the sides of their bodies that resemble hair. In theory, these strands also allow the frogs to take in more oxygen while they watch over their eggs. But what's really compelling about this frog is its ability to crack its own toe bones and push them through their skin to form sharp claws, which are great for warding off would-be attackers.

While it's not completely clear what happens to the bones after the threat of attack subsides, researchers believe the bones slide back under the skin when the frog's muscles relax.

3. THE NEWT THAT TURNS ITS RIBS INTO SPIKES

David Perez, Wikimedia Commons // CC BY 3.0

The hairy frog isn't the only amphibian that uses its bones for weapons. When attacked, the Spanish ribbed newt shifts its ribs forward at an angle and pushes them through its stretched skin. The resulting effect is a row of spikes on either side of its body. Like the hairy frog, the newt has to force the bones through its skin every time it is attacked, but the mechanism seems to cause little or no harm to the creature. Maybe one day it'll get its own robot protector: A team of researchers at the the Swiss university EPFL created a robotic salamander inspired by the newt, which they called the Pleurobot (after its scientific name, Pleurodeles waltl).

4. THE TERMITE THAT BLOWS ITSELF UP

Talk about taking one for the team. When under attack, a species of termites found in the French Guiana rain forests sends older worker bugs on suicide missions to defend the whole colony. These older bugs, no longer as useful to the pack as they once were, come equipped with "explosive backpacks" that, over a lifetime, fill with toxic crystals produced by glands in the abdomen. When mixed with salivary gland secretions, these crystals create a toxic liquid that explodes on enemies, paralyzing them and killing the worker at the same time. These termites aren't alone among insects in using a suicidal defensive tactic: When faced with a threat, an ant found in Borneo expands its abdomen until it ruptures, shooting out a toxic liquid

5. THE FISH THAT SLIMES ITS ENEMIES

Hagfish are eel-shaped marine animals with the incredibly useful ability to slime their enemies. When threatened, the hagfish emit a slime from their pores that, when mixed with water, expands into a gelatinous goo that can either trap predators or suffocate them by clogging their gills. The video above shows a hagfish being attacked 14 separate times by sharks and other big fish, and coming out completely unharmed. Each predator took one bite before immediately spitting the hagfish out and swimming away, gagging. The best time to encounter a hagfish is probably after it's emptied its slime glands withstanding such an onslaught; the glands take three to four weeks to refill.

6. THE SEA CUCUMBER THAT SHOOTS ORGANS OUT OF ITS ANUS

iStock

Sea cucumbers can seem pretty boring. There are some 1250 known species of these sedentary creatures in the world, and many of them do indeed look like cucumbers. But when it comes to survival, things get interesting. Like starfish and sea urchins, sea cucumbers are echinoderms, and they can regenerate lost body parts if necessary. This comes in handy when they're threatened. The sea cucumber will expel its internal organs, which are sticky and sometimes contain a toxic chemical that can kill predators. They don't have much of a defense against pollution though, which is a problem, because they're superstar ocean-floor cleaners.

7. THE OPOSSUM THAT PLAYS DEAD

Tony Alter, Flickr // CC BY 2.0

You can't do a roundup like this without at least mentioning the opossum. We typically refer to this creature's infamous defense mechanism as "playing dead," but there's actually nothing playful about it; the act is completely involuntary. Under intense fear, opossums fall into a comatose-like state that can last for hours, long enough to convince any predator that the opossum is already dead. Also unappetizing: Fear causes these animals to emit a corpse-like smell that only adds to their act. Thank the opossum for providing some defense for us too: They eat venomous snakes and ticks, gobbling up to 4000 insects a week.

Amazon’s Big Fall Sale Features Deals on Electronics, Kitchen Appliances, and Home Décor

Dash/Keurig
Dash/Keurig

If you're looking for deals on items like Keurigs, BISSELL vacuums, and essential oil diffusers, it's usually pretty slim pickings until the holiday sales roll around. Thankfully, Amazon is starting these deals a little earlier with their Big Fall Sale, where customers can get up to 20 percent off everything from home decor to WFH essentials and kitchen gadgets. Now you won’t have to wait until Black Friday for the deal you need. Make sure to see all the deals that the sale has to offer here and check out our favorites below.

Electronics

Dash/Amazon

- BISSELL Lightweight Upright Vacuum Cleaner $170 (save $60)

- Dash Deluxe Air Fryer $80 (save $20)

- Dash Rapid 6-Egg Cooker $17 (save $3)

- Keurig K-Café Single Coffee Maker $169 (save $30)

- COMFEE Toaster Oven $29 (save $9)

- AmazonBasics 1500W Oscillating Ceramic Heater $31 (save $4)

Home office Essentials

HP/Amazon

- HP Neverstop Laser Printer $250 (save $30)

- HP ScanJet Pro 2500 f1 Flatbed OCR Scanner $274 (save $25)

- HP Printer Paper (500 Sheets) $5 (save $2)

- Mead Composition Books Pack of 5 Ruled Notebooks $11 (save $2)

- Swingline Desktop Hole Punch $7 (save $17)

- Officemate OIC Achieva Side Load Letter Tray $15 (save $7)

- PILOT G2 Premium Rolling Ball Gel Pens 12-Pack $10 (save $3)

Toys and games

Selieve/Amazon

- Selieve Toys Old Children's Walkie Talkies $17 (save $7)

- Yard Games Giant Tumbling Timbers $59 (save $21)

- Duckura Jump Rocket Launchers $11 (save $17)

- EXERCISE N PLAY Automatic Launcher Baseball Bat $14 (save $29)

- Holy Stone HS165 GPS Drones with 2K HD Camera $95 (save $40)

Home Improvement

DEWALT/Amazon

- DEWALT 20V MAX LED Hand Held Work Light $54 (save $65)

- Duck EZ Packing Tape with Dispenser, 6 Rolls $11 (save $6)

- Bissell MultiClean Wet/Dry Garage Auto Vacuum $111 (save $39)

- Full Circle Sinksational Sink Strainer with Stopper $5 (save $2)

Home Décor

NECA/Amazon

- A Christmas Story 20-Inch Leg Lamp Prop Replica by NECA $41 save $5

- SYLVANIA 100 LED Warm White Mini Lights $8 (save 2)

- Yankee Candle Large Jar Candle Vanilla Cupcake $17 (save $12)

- Malden 8-Opening Matted Collage Picture Frame $20 (save $8)

- Lush Decor Blue and Gray Flower Curtains Pair $57 (save $55)

- LEVOIT Essential Oil Diffuser $25 (save $5)

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Why Do Dogs Like to Bury Things?

Dogs like to dig.
Dogs like to dig.
Nickos/iStock via Getty Images

If you’ve ever found your dog’s favorite toy nestled between pillows or under a pile of loose dirt in the backyard, then you’ve probably come to understand that dogs like to bury things. Like many of their behaviors, digging is an instinct. But where does that impulse come from?

Cesar's Way explains that before dogs were domesticated and enjoyed bags of processed dog food set out in a bowl by their helpful human friends, they were responsible for feeding themselves. If they caught a meal, it was important to keep other dogs from running off with it. To help protect their food supply, it was necessary to bury it. Obscuring it under dirt helped keep other dogs off the scent.

This behavior persists even when a dog knows some kibble is on the menu. It may also manifest itself when a dog has more on its plate than it can enjoy at any one time. The ground is a good place to keep something for later.

But food isn’t the only reason a dog will start digging. If they’ve nabbed something of yours, like a television remote, they may be expressing a desire to play.

Some dog breeds are more prone to digging than others. Terriers, dachshunds, beagles, basset hounds, and miniature schnauzers go burrowing more often than others, though pretty much any dog will exhibit the behavior at times. While there’s nothing inherently harmful about it, you should always be sure a dog in your backyard isn’t being exposed to any lawn care products or other chemicals that could prove harmful. You should also probably keep your remote in a safe place, before the dog decides to relocate it for you.

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