We're wrapping up Sex Ed Week at Motherboard, and it would be a crime to let it pass by without delving into the kinkiest behaviors in the animal kingdom. There is a huge diversity of seduction tactics in nature, from the diplomatic nymphomania of bonobos to the non-existent libidos of panda bears. But you already know about all that. What follows is the flat-out gnarliest mating rituals, categorized for your convenience. Life finds a way all right...a disturbing, messed up way.

Boy Meets Girl, Girl Eats Boy

Let's start out this list strong with sexual cannibalism—the death metal of mating rituals. This behavior is most often observed in spiders and mantids and features the female eating the male either before, during, or after copulation. Usually, this is a way to nourish the pair's offspring, but there are all sorts of disturbing variants on the ritual, including females that straight-up lie to males about their cruel intentions.

Though females are normally the freaky practitioners of sexual cannibalism, some male wolf spiders have been observed chowing down on older females of their species, presumably because they have lost reproductive value. Chivalry is stone cold dead when it comes to wolf spiders, it would seem.

Incidentally, sexual cannibalism isn't the only behavior in which sex and death are inextricably linked. The mouse-like marsupial called the antechinus has evolved a bombastic mating life in which the males only mate once, but go all out for the endeavor—they will have sex with any female in sight over a period of weeks, with each lovemaking session lasting up to 14 hours.

This so-called "big bang" approach to reproduction is so all-consuming that the males physically disintegrate by the end of it, and ultimately perish of exhaustion. It's nature's riff on the "Death by Snu Snu" Futurama episode.

The Detachable Penis

There is a dazzlingly bizarre parable in the Malleus Maleficarum—the demented Medieval guide to witch prosecution—that describes a bunch of disembodied human penises nesting together under the spell of witchcraft. Whatever patriarchal fever dream that story was supposed to inform, it turns out that detachable penises aren't actually that rare in nature.

Male wasp spiders, for example, are known for self-castrating mid-coitus, effectively plugging the female reproductive tract so that other males can't access it. The genitalia of honey bees actually full-on explodes inside the female, earning the term "sexual suicide." It's a high stakes way to lock down paternity, but it works, and a surprising diversity of animals use these so-called "mating plugs."

By far the most impressive detachable dick, however, belongs to the octopus species Argonauta argo. It develops under the octopus's eyeball, and eventually busts out like Athena breaking open Zeus's skull, killing the male. It then swims independently until it can latch onto a female, and eventually fertilize her eggs. Weird? Yes. Frightening? No question. Awesome? Undoubtedly.

Female Argonauta argo with eggs. Image: Bernd Hofmann

The Overly Attached Boyfriend

There is a lot to love about the anglerfish: its entrancingly monstrous appearance, its bioluminescent lure, and its alien, deep-sea habitat. But perhaps the craziest thing about these animals is their sex life, which is shaped by extreme sexual dimorphism. Male anglerfish are so tiny compared to females that scientists assumed they were parasites for several decades, and in a way, they are.

Anglerfish mating habits. Credit: NatGeoWild/YouTube

Here's how the lovin' goes down: a male anglerfish will follow a trail of female anglerfish pheromones, and when he finds her, he'll bite into her, latching onto her flesh. Then, the male just slowly morphs into her body, sharing her blood vessels and letting his independent organs atrophy. Essentially, he becomes a little sperm side pocket; the embodiment of the song "2 Become 1" by the Spice Girls. Creepy as all hell, but it seems to suit these weirdos just fine.

The Overly Psychotic Boyfriend

All the way over on the other side of the lovemaking spectrum from anglerfish codependency is "traumatic insemination," a behavior every bit as terrifying as it sounds. Exemplified by the horror show that is bedbug copulation, traumatic insemination is basically when a male impales a female with his appendage of deathly love, and then ejaculates into her wounds.

A male bed bug traumatically inseminates a female bed bug, cracking her exoskeleton. Image: Rickard Ignell, Swedish University of Agricultural Sciences

This process is incredibly damaging to the female's body, a fact that has generated a lot of debate among biologists over why male bedbugs have to be such unrepentant little demons about it.

But sadly, male bedbugs aren't the only psychotic lovers in nature. The male water strider also has a ballsy seduction technique, in which he purposely tries to attract predators to the female by flailing about on the water's surface. The male's reckless behavior intimidates the female into putting out, and quickly, lest both of them end up in a fish belly. It's a bold move Cotton, let's see if it'll pay off.

The Scary Dog Pile of Suffering

The only thing scarier than the sadistic males described above is a big-ass group of them working together. A disturbing number of species employ a violent mob mentality when it comes to begetting the next generation, and a lot of them are fan favorites, like dolphins, seals, and ducks.

I am going to single out ducks on this one, because they are the absolute worst offenders in this sordid arena. Male ducks are so sexually coercive that female ducks have evolved corkscrew vaginas to mitigate risk of being fertilized by the most vicious among them. In a horrendous ritual known as a "rape flight," male ducks will attack a lone female and peck at her until she mates or dies.

Male ducks will also sexually assault each other, and will even copulate with dead male ducks. The fact that this unintimidating, pastoral bird has evolved such a perverted reproductive behavior is truly one of nature's most hamfisted jokes.

The Garden of Semen

After all that talk of rape flights and traumatic insemination, it's time for an uplifting mating ritual. Still totally mind-boggling, of course, but not depressingly so. Enter: the red velvet mite, forever immortalized in this Oatmeal comic.

Much like the artistically inclined bowerbird, the red velvet mite advertises its sexual desirability by building what biologists call a "love garden." It's a beautiful nest decorated and supported by the male's semen. If a female mite is impressed by it, she'll agree to come home with him and impregnate herself on the sperm-covered furnishings.

A red velvet mite. Image: Ton Rulkens

If, however, a rival male comes across an untended love garden, he will destroy it, then ejaculate all over it, so that any females that stop by will be impregnated by his sperm. It turns out that not even a soulful species like the red velvet mite is entirely without assholes.

The Bodily Fluid Fetish

Why limit yourself to sperm-laden love gardens? That's what Mother Nature clearly asked herself, because it turns out that red velvet mites are far from the only species that endorse the use of bodily fluids in foreplay.

The male white fronted amazon, for example, displays affection by vomiting into the mouth of its paramor. Male giraffes flirt by chugging a little female urine, which helps them gauge where the female is at in her estrus cycle. Likewise, porcupines likewise won't get it on until the male has unleashed a powerful golden shower onto the female.

But when it comes to being aroused by all things scatalogical, no animal can outdo the hippopotamus. In a move known as the "poop helicopter" or the "hippo butt explosion," male hippos will fling their feces and urine around by spinning their tails, thus warning other males to stay off their turf, while attracting prospective females. Because when it comes to selecting a mate, nothing is more enticing to a female hippo than a dude that really knows how to launch some poo.

Hippos pooping in each other's face. Credit: Deborah Durand/YouTube

Gender Bending

Hermaphroditic animals not only have to seek out a mate, they have to decide which gender to be once they've found their significant other. Flatworms solve this dilemma by with a ritual known as "penis fencing," which is exactly what it sounds like (and also occurs in bonobos for entirely different reasons).

Flatworms penis fencing. Image: Nico Michiels.-Whitfield J

Each flatworm is endowed with two penises, which they use to puncture the skin of their rival/lover, in a violent race to inseminate the other first. The first to land a serious punch gets to be the father—on that round, at least. It's odd to think that some flatworms might experience both sides of parenthood within one lifetime.

Interestingly enough, same sex copulation also occurs in the animal kingdom. The whiptail lizard defies convention by having populations that are entirely female, a la Jurassic Park. Though they reproduce asexually, the females simulate breeding behavior with each other, taking turns at being bottom and top. There is still a debate whether or not miming sex induces fertility in the lizards, but regardless, the lizards seem to get a kick out of it.

Interspecies Action

These puzzling couplings have earned the delightful terms "misdirected mating" or "reproductive interference," and they are widespread in nature. Indeed, most people of European descent have interspecies breeding stamped in their DNA, a memento of the brief human-Neanderthal love affair that occurred some 54,000 years ago. Not even humans are immune to the call of extra-species fornication (and let's not even get into bestial Mr. Hands territory…*shudder*).

To sum up, life on Earth has evolved a fascinating diversity of sexual kinks, from hopelessly adorable to downright horrifying. With Valentine's Day approaching, it's a good time to reflect on what your spirit animal is in this arena, whether it's a hopeless romantic like the red velvet mite, a player, like the sexually crazed antechinus, or a creepy parasite, like the male anglerfish.