“When slugs mate, they rub their g—ls together. If they get stuck or are unable to mate successfully, one slug has to bite of the other slug's g—ls.”

“female hyenas have no vaginal opening, and give birth through the c—s, which *ruptures* as a natural part of the process.”

“Sloths keep their stomach full because their diet is not very nutritious. If their body temperature drops too low, the bacteria responsible of the food process stops working, which can make the sloth starve to death, even with a full belly.”

“If you turn a shark belly up it goes into a completely immobilized trance. Incidentally, orcas figured this out, and they use this on great white sharks. Knowing that the shark is always looking up at the surface to spot its prey, the orca will sneak up on it from below and flip it over, then eat the shark's liver and leave the rest of the body behind. Scientists aren't sure why they do it. They could be doing it to remove their competition from the hunting area, or they could do it because they really like shark liver -- Or what I find to be the most interesting possibility, it could be that they do it simply for sport.”

“Ferrets: If female ferrets go into heat and do not get pregnant, they die from estrogen build up. If this happened to human girls... high school would be like the hunger games.”

Notably lacking a swim bladder — a.k.a. the organ that prevents fish from floating to the surface to sinking to the bottom of the ocean — Sunfish contain pockets of lipids that keep them at a reasonable depth, hence why they look like that.

“Babirusa pigs. If babirusa don't wear down their tusks, they can continue to grow until they pierce the pig's skull.”

"Any way you look at it, these little guys have failed at evolution. They pretty much only eat Eucalyptus. This is just bad for survival in general, as if Eucalyptus is destroyed within their habitats, they will likely starve. It also means that if too many Koalas occupy to same area, there will not be enough food to go around (these are both true for all species, but Koalas make themselves even more vulnerable by relying on one food source). Additionally, since gum trees like Eucalyptus are fibrous and low in nutrition, Koalas have to rest up to 22 hours a day, as Eucalyptus take a lot of energy to digest. Not only have they specialized into eating one single type of food, that food inhibits their general day to day functions as a result."

“Pugs, although cute, got seriously f—ed over genetics wise. I have never met a pug who didn't have breathing problems.”

“Hands down has to be red algae's s—m cells being unflagellated. They reproduce externally in the water, and because their s—m cells cannot move they have to hope that ocean waves will push the s—m cells to the egg cells drifting in the water. Their haploid generation is so awful at reproducing that they need a third generation to xerox copy the zygotes just to make sure red algae don't go extinct. They are the only clade to alternate between three generations instead of two.”

“Giraffes have an internal organ that literally makes the trip all the way up the neck and comes back down for no reason other than evolution isn’t much of an intelligent designer.”

“Hairless cats. They get sunburnt outside and can’t keep themselves warm.”

“Pandas. Everything about pandas. They can barely digest bamboo but it's also their only food source so they just eat a LOT of it to compensate. Also they can only raise one child at a time and if they have twins, they'll just leave the weaker one to die. It's pretty impressive they're capable of existing really.”

“Male Elephants - More specifically, when they're in Musth. Basically, their testosterone sky-rockets, and they become a danger to themselves and their herds.”

“Snails. Pour a little salt on them, and they immediately die from dehydration as the moisture is pulled from their cells.”

“Sea snakes can die of thirst and rely on rainwater to make pools on the ocean surface in order to survive.”

“The Kakapo doesn't have much going for it. The bird can't fly and can barely walk. To attract females, the male will dig a hole and sit in it, shouting loudly at any female passing by. Rarely does this work, so it waddles off to find a rock and has s–x with that instead.”

“Horses. Everything about horses. When they pee, they can’t push it all out so they get UTIs almost all of the time. Also, their stomachs can get flipped over on themselves and cut off circulation, rot away and kill the horse. Just from laying down and rolling around. Stupid animals and I hate them. Also horses are pretty cool.”