by Megan Hauptman, Lili Rosenkranz, Josh Schenkkan, John White & Emma Wohl

Illustration by Jackie Rent

published October 3, 2013

A few weeks ago, as we were dragging our fingers through the water and dangling our feet off the dock, a duck drifted toward us. There was just ripples and treading; the beak and the body. Someone shouts, “Did you know that….” A lake duck’s penis uncoils, sometimes up to five feet. The female’s vagina has adapted to adopt the torsion. Something much stranger is transpiring under the surface. So, we crane our necks. We are curious; we try to peek. Seeing nothing, we turn to ancient texts, to tattered encyclopedias and yellowing journals, to the darkest recesses of the Internet, searching for what happens underwater, overland and mid-flight. Here’s what we found.





Two spiral-coiled shells slowly circle each other among the garden muck. The eyestalks emerge first, wiggling in anticipation, then the soft bodies start to ooze toward each other. Both snails shoot calcium love-darts into the neck of the other—these mucus-coated harpoons are supposed to increase the potency and viability of the snails’ sperm, but if poorly aimed, they can also kill the receiver. Then the two warriors press the undersides of their bodies up against each other, their white sexual organs sliming together like two messily French-kissing tongues. 

     Snails are hermaphroditic. Some snails choose one sex when mating, while others can ovulate and inseminate at the same time. A few varieties of snails can also reproduce asexually; females can clone their female offspring without male fertilization. Despite the fact that it requires more energy and is not necessary for the species’ procreation, these snails still have partnered sex. 

     In March of this year, University of Iowa scientists received $876,752 in National Science Foundation grants to study the phenomenon of sexual reproduction in a species that can reproduce more efficiently asexually. The abstract for the project asks a big question: “Why is sexual reproduction so common despite its costs?” In a TV segment criticizing excessive government spending on scientific studies, Fox News anchor Neil Cavuto offered his theory: “Just hazarding a guess. May be more fun.” –MH



The voracious sexual appetite of rabbits is notorious. Unlike other mammals that go into heat at certain points of the year, they go at it year-round. Their sessions are brief but frequent, punctuated by short naps. But for bunnies as for the rest of the Animal Kingdon, sex is not all about satisfaction—it’s about continuing the species without giving up their carefree, rather defenseless nature. And it begins a short 12 hours after sex, when a female rabbit will release ovaries, which can become inseminated almost immediately.

     From there, it is only about a month until her babies are born, in a large litter of up to 12. Some estimates suggest that a single female rabbit and her offspring could potentially produce 184,597,433,860 rabbits in seven years. That number, in case your eyes glazed over it, is over one hundred billion.

     These estimates are based on a few, slightly unrealistic criteria: that the rabbit would become pregnant immediately on beginning to ovulate after her last pregnancy, which happens in a matter of minutes; that rabbit reproduction occurs year-round, when in fact it is generally concentrated between February and October; that the rabbit will live for seven years, which is longer than projected. But still, the number could easily be in the millions—all coming from a single matriarch.

      So if rabbits are reproducing by the millions, why are we not commonly stumbling over floppy-eared younglings, finding them under our pillows, gifting them to our sweethearts as an easily available sign of our attraction? In the areas to which they are native, rabbits are surrounded by predators, so there’s an added urgency to the fevered coupling of parents striving to continue the species. It’s breed or die out, and these bunnies and their honeys are more than happy to fight the good fight to keep their species alive. –EW



Whoever said that there are plenty of fish in the sea has clearly never hit rock bottom. At 3,300 to 6,600 feet down in the deep, dark ocean, it is hard for Ceratiidae, or deep-sea anglerfish, to find love. Anglerfishes’ trademark bioluminescent lure—a movable extension of bone that sprouts from the middle of their heads and terminates in a glowing ball of flesh—helps them find food (or rather, food find them) in the darkness. But what about finding mates? Evolution found an answer: Male ceratioids, though 40 times smaller than females and ill-equipped to survive on their own, have excellent olfactory organs that help them detect females’ pheromones soon after birth. The undiscriminating male anglerfish bites into the skin of the first female he finds. He then releases an enzyme that digests the skin of his mouth and her body so that the pair become permanently fused together. Once bitten, the female provides nutrients for the male via their shared circulatory system. The male’s body atrophies as his testicles grow so that, when the female is ready to reproduce, he can provide her with sperm. Deep-sea polygamy is not out of the question: In the interest of efficiency, multiple males can easily merge with one female if she is the first they encounter. When scientists started studying ceratioids, they initially found what they thought were females with extra appendages that appeared to be parasites. But no, they were the males of the species. –JW



Fred had been born a honeybee, but at times he wished he had been born a bird, or perhaps an elephant. There were the obvious advantages, of course: a bird can soar to heights of which a bee can only dream, and an elephant fears no bug-zapper. But more than anything, neither a bird nor an elephant has genitals that literally explode on ejaculation, causing a less-than-petite ­mort.

     The male honeybee, called a “drone,” is one of a number of animals and insects that commit sexual suicide. Upon ejaculation, the drone’s penis explodes, tearing his abdomen open and ultimately killing him. Nature is brutal in its efficiency—the drone’s sole function is to fertilize the queen, and once this function is performed, the drone would become just another mouth for the hive to feed. Dying in climax, however, might be nature’s way of saying it’s better to go out with a bang than a whimper; if a drone fails to mate with the queen, he will be turned away from the hive and left to freeze to death in the coming winter, blue balls in the most literal sense. –JS



Swan sex isn’t all that weird. In fact, that’s what’s maybe what’s weirdest about it—you basically know how it works already. The story goes like this: Leda, mother of Helen of Troy, slept with the Greek god Zeus while he was a swan—and while the part about her giving birth to the most beautiful woman ever by laying an egg is just creative license, the physical logistics of their conquest make more sense when you understand one thing.

     Swans have penises. This is only true of flightless and water-bound birds, but not the vast majority of the species. Those that fly were designed to be as light as possible, shedding themselves of all unnecessary weight through evolution—excess weight that included external sexual organs. Most birds have a single organ, the cloaca, which functions as bladder, waste receptacle, anus, and sexual organs. They rub against their mate’s cloaca to really get things going.

     Swans, it seems, are not so secure in their masculinity. Their penis is shaped like a spiral and has no urethra, because birds do not produce urine. It becomes erect, not as in humans by blood rushing to it, but through lymphatic pressure—a more efficient pressure requiring less weight. This allows them to mate under water with far more grace and a much higher rate of satisfaction than the kids down the street breaking into the neighbor’s pool. –EW



The male praying mantis mounts the female from behind. He seizes her thorax and restrains her wings with his forearms. He arches his abdomen, rummaging for her abdomen. As he clampers, she clutches the branch. The weevils scatter and she lets him control her in joint-bending shifting, in a tightrope walk where she must let him hold her, all of her, across the twigs.

     But once the male has climaxed, when he starts to withdraw to find fruit flies to eat or another partner to mate with, the female will dart backwards, rotating her head to peck at his eyes. Only then does it become obvious that the female is much larger with twice the wingspan. He flails in her arms; she pins him to the tree and bites off his head, sucking green body fluid out of his skull. Her partner and prey is the nearest high-energy meal. Sexual cannibalism means she is fertilized and full. The father is sacrificed for the sake of his offspring. Love kills. –LR