7 Animals With Sex Lives That Make Humans Look Vanilla

If you want proof the animal kingdom is queer, kinky and gender-bending, look no further.

Two hippos mating in the water.
Credit: Bernard Dupont

Explainer Research Science

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The animal kingdom is extraordinarily diverse, but there’s one thing all animals have in common: they reproduce. That’s where the similarities end, however. The mating practices of Earth’s creatures are about as diverse and varied as the creatures themselves, and a great number of animals have queer and gender-bending sex lives that make most human sex seem positively quaint by comparison.

No matter how crafty, smart or hardy a species is, it will quickly become extinct if it can’t reproduce at a high enough rate. But for many creatures, that’s easier said than done. An animal’s ability to reproduce successfully is restrained by its habitat and population density, as well as environmental factors, predators and even the animal’s own biology. If a species can’t overcome the obstacles that the factors present, it’s toast.

But as Jurassic Park taught us, life finds a way. The animal kingdom has developed some truly extraordinary methods for successfully passing on genes to the next generation; they might be weird, disgusting, funny or even violent, but the mating practices in this list are a testament to the adaptability of living creatures, even in the face of remarkable odds.


The female anglerfish is between 10 and 60 times bigger than her male counterpart. When they cross paths in the deep sea, the male bites into the female’s side, latches on and doesn’t let go — ever. This is where he’ll remain for the rest of his life; over time, his body becomes permanently grafted to the female’s, and the two develop a shared circulatory system.

At this point, the male gets to enjoy a relatively stress-free life, as he relies entirely on the female to do the hard work of eating and surviving. The female, in turn, gets a constant and reliable supply of sperm without ever having to seek out another partner.

Interestingly, despite the fact that male and female anglerfish are fused together into one body, the actual act of reproduction takes place externally, as they each release sperm and eggs into the surrounding water simultaneously.


Flatworms are hermaphrodites, and they’re notable for having two entirely different methods of reproduction. In normal situations, they’ll reproduce sexually — although their method of doing so is far from normal. The mating ritual begins with two flatworms extending their penises and having what can only be described as a swordfight. Whichever one is “stabbed” first becomes impregnated.

But when their environments are stressful, dangerous or lacking in mates, flatworms can also reproduce asexually. They do this either by splitting themselves in half, with each half becoming its own worm, or through a process called budding, whereby they grow a chain of buds on their bodies that gradually split off into a new organism.


In order to understand clownfish reproduction, we first have to understand their social structure. In a group of clownfish, there will be one dominant female, one breeding male with whom she mates, and many other non-breeding males with underdeveloped sex organs.

It’s when the female dies that things get weird. Should the dominant female clownfish pass away, the largest male in the group will become female — an ability that all clownfish are born with — and assume her new role as the dominant female. Meanwhile, the second-largest male will step up to the plate and become the new breeding male.


Credit: Bernard Dupont/Flickr

Nobody would accuse hippos of being overly romantic. In fact, their sex is so X-rated we can’t even embed a video of it here.

Their courtship begins with the male hippo defecating and urinating at the same time, then whipping his tail around furiously in order to send the mess flying through the air. Should this pique the interest of a nearby female — and it often does, for reasons we may never understand — she’ll return the favor by turning around and emptying her bowels onto him, a move scientists refer to as “submissive defecation.”

Then they have sex.

New Mexico Whiptail

Every New Mexico whiptail lizard is female, and they produce asexually. They have neither the need nor the ability to have sex, but they’ll often pretend to: female whiptails frequently mount one another and act as if they’re a male and female in the throes of passion, even though no sex is actually being had.

But the practice apparently isn’t entirely just queer fun. Studies have shown that whiptails who engage in this faux-sex — specifically, the “bottoms” — are more fertile and lay more eggs than whiptails who don’t.

As an all-female species that can reproduce without men, New Mexico whiptails have become popular in some queer communities, with some referring to them as the “leaping lesbian lizard.”


The antechinus is an adorable, mouse-like marsupial, but their mating practices are anything but adorable. Once they’re a little less than a year old, male antechinuses suddenly stop producing sperm, and begin frantically mating with any and all females they can find. These sessions can last up to 14 hours straight, and are often extremely high-energy affairs. After one to three weeks of this, all of the male antechinus abruptly drop dead, poisoned to death by their own surging hormones.

But antechinus are nothing if not resourceful: After this mass die-off, remaining antechinus in the area will feast on the corpses of the dead.


When a male giraffe is interested in a female, he’ll nudge her butt with his head. If she’s receptive to his advances, she’ll urinate into his mouth so that he can smell her pheromones. If he likes what he smells, he’ll start following her around as she walks away from him. This will continue for several days until eventually, the female giraffe finally stops walking long enough for the male to mount her. He’ll ejaculate within seconds, and the two will then part ways forever.

It’s also extremely common for male giraffes to mount one another and do something that looks a lot like mating. There’s substantial disagreement among giraffe experts on whether this is actually a mating attempt or a battle for dominance, but it’s been witnessed in females as well as males, and in one study, 94 percent of observed sexual activity between giraffes were between two males.

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