weird 20 Bizarre Anatomical Features Of Common Animals  

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Pet owners and animal lovers think of their favorite animals as non-human people. With their range of personalities, behaviors, and habits, it’s hard not to see why...until you delve into the uncommon anatomy of common animals. After that,  it’s hard to forget that humans and animals are not the same. From missing body parts to extra appendages, some animals are just plain bizarre. 

Dogs Can Retract Their Eyeballs into Their Sockets

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Photo: djwhelan/flickr/CC-BY-NC-ND 2.0
If you’ve ever tried to give your dog eye drops, you may have noticed that the eyeball seems to disappear. Dogs don’t have magical eyeballs, but they do have a wondrous set of muscles called retractor bulbi. These muscles allow dogs to retract their eyeballs into their sockets, far away from that eye dropper (or anything else they don’t want near their eyes). 

Woodpeckers Have a Bone in Their Insanely Long Tongues

Woodpeckers Have a Bone in The... is listed (or ranked) 2 on the list 20 Bizarre Anatomical Features Of Common Animals
Photo:  G. Shriver/
The anatomy of a woodpecker’s tongue is so mind-boggling it might take a few head bumps off a tree to make sense of it. These freakishly long tongues extend from the throat to the jaw, past the sinus cavities, around the brain, and down through the nostril. Woodpeckers’ tongues are solid at the beginning, split for some of the long journey, and reunite at the tip. No wonder Winnie Woodpecker never complained. 

As if that wasn’t crazy enough, woodpecker's have a bone in their tongues; they can peck through a lot more than trees.  

Argonaut Octopuses Have Detatchable Penises

Argonaut Octopuses Have Detatc... is listed (or ranked) 3 on the list 20 Bizarre Anatomical Features Of Common Animals
Photo:  olafpictures/Pixabay/CC0 1.0
In usual mating situations, the male spreads his seed and the female pretty much just lets him. Then there are Argonaut octopuses, truly unique in the animal kingdom. A male Argonaut keeps his sperm in a detachable tentacle – yes, that’s what it’s technically called – and throws said tentacle in the general direction of a female, so she can fertilize herself. After detaching his, errr, special tentacle, the male dies. The female shows her appreciation by collecting the spermy tentacles from different ‘donors’ and fertilizing herself as often as she wants. How’s that for the most impersonal (and horrifying) mating ritual imaginable? No wonder the Argonaut octopus dildo market was DOA.  

Almost 10 Percent of Cat Bones Are in the Tails

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Photo: Trish Hamme/flickr/CC-BY 2.0
Cats use their tails to share their mood and to land on their feet when they jump (or fall) from that bookcase you keep telling them not to climb. Their tails aren’t just handy tools to keep their humans from hyperventilating. Cats’ tails are complex anatomical structures that keep them balanced – so complex, in fact, that they house ten percent of a feline’s bones. With about 20 vertebrae in their tails alone (give or take depending on their breeds), it’s no wonder cats express their feelings through their most complicated appendages!  

Female Hyenas Have Pseudo-Penises

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Video: YouTube
In a bizarre trick of evolution (or lack thereof), female hyenas have super masculine genitals. What looks like a penis (often referred to as a "pseudo-penis") is actually an extremely large clitoris. Hanging down approximately seven inches, this appendage has a way of making male hyenas feel bad about themselves. 

As the dominant hyena sex, females have no problem attacking would-be-suitors. If a male wants to be intimate, he has to show his submission. If the female doesn't attack him right away, there's still have the obstacle of basically trying to squeeze a penis into a penis.

If mating is successful, female hyenas have to go through the pain of child birth -- the only thing more painful and awkward than mating. While trying to squeeze a baby hyena out of a one inch tube, everyone involved is in danger. First time hyena mothers often bleed to death. If the mother survives, she still has to face the death of most of her offspring who suffocate on the long, narrow road. 

When put into context, it's not hard to see why female hyenas are the alpha gender!   

Kangaroos Have Three Vaginas

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Proving that good things really do come in threes, female kangaroos, koala bears, Tasmanian devils, and wombats all have three vaginas. So what makes the kangaroo so special? Well, along with their three vaginas, kangaroos also have two uteruses (or uteri, depending on your word preference).

The three vaginas are arranged like a trident, the uteruses sitting between the trident prongs. The left and right vaginal canals are used as sperm tunnels and the middle vagina is the birthing canal. Baby kangaroos (joeys) are about the size of a bean when they're born, because there's a lot going on in there, and little room to spare. 

Kangaroos can get pregnant in both uteruses at the same time, give birth to a joey, store said joey in their pouch, and then keep the cycle going. Basically, kangaroos are always pregnant, pretty much guaranteeing that their species won't be endangered any time soon. 

Chickens Sometimes Change Genders

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Photo:  Skyangel/Pixabay/CC0 1.0
Forget about the age old question about the chicken and the egg. This is a lesson about the chicken and the rooster -- or rather, the chicken who becomes the rooster.

During the embryonic stage, chickens have two gonads. The left gonad turns into an ovary or testicle and the right one just sort of sits there. When the sex gene produces a female, the hen will be born with an ovary and all the hormones that go with it.

If something goes wrong with the left ovary, a hen's body goes into a bit of a panic. That's when the right gonad that was previously useless comes into play. In rare but real circumstances, the right gonad can start acting as a testes and release male hormones into the hen. At this point, the chicken will lose the ability to lay eggs and develop unladylike characteristics. The gender-confused chicken doesn't become the total rooster package, but she will look, sound, and act like a rooster. 

Cock-a-doodle-doo, indeed! 

Hamsters Cheek Pouches Extend from Mouth to Hip

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Photo: necrocake/flickr/CC-BY 2.0
Everyone knows that hamsters, chipmunks, squirrels, and the majority of furry critters store food in their cheeks. Most people don't realize how much. In first place for storing as much food as possible, hamster's cheek pouches extend all the way from their mouths to their hips. Relative to a hamster's size, that's a whole lot of food, making them leaders in the anatomical storage space sweepstakes.