There are many valid reasons that we, as humans, can be afraid to reproduce ourselves, but none of these reasons is the actual act of reproduction, judging by how effective we’ve become at practicing it while avoiding most of its implications. We’ve got our evolutionary history to thank for our relatively straightforward mating system and also for the uncontrollable shivers down our spines that happen when we learn about how other creatures produce offspring.
The praying mantis female feasting upon the male is a classic example. This behaviour, termed sexual cannibalism, is overall rare among animals but common in insects and arachnids. The structure of the nervous system allows the male to continue copulating while it is being eaten. So even if he has lost his life, the male has accomplished his purpose: he successfully passed his genes onto the next generation. Males of some spiders have reached compromises, such as the red back spiders that squeeze their waists to relocate vital organs and not be killed by the oversized female’s first bite and gain extra time to copulate, or the golden orb spiders that bind the females with silk until sperm transfer is finished.
In bed bugs, the situation is somehow reversed: males forcefully mate with females by injecting sperm into their abdomen. This is aptly termed “traumatic insemination” and, as the name suggests, it is relatively costly for the female. It is not yet fully understood how sperm migrates through the female’s body to her reproductive tract, but some species have modified their abdominal area to various extents to assist with this function.
Gruesome mating habits are present even if separate genders are not. Snails are hermaphrodites- all individuals possess both male and female sexual organs and reproduce by exchanging sperm. During courtship, they stab their mates with calcareous darts containing a substance that works its way through the “stabbed” partner’s body to ensure the sperm they’ve just received will be used to fertilize their eggs.
Some marine flatworms, other hermaphrodite species, go to impressive lengths to avoid assuming the energetically demanding role of the mother for their offspring. What seems to be an elegantly coordinated courtship dance is nothing but “penis fencing”: each individual tries to inseminate the other by inserting one of the two penises located ventrally, at the front, anywhere through the partner’s skin. The sperm will find its way through the loser’s body, which is now stuck with the fertilized eggs to take care of.
Probably one of the most extreme reproductive strategies in the animal kingdom is seen in some species of angler fish. Unfairly described as true monsters from the abyss, the ugliest animals on Earth, angler fish are just very well adapted to the deep sea they live in and they’re doing a great job in a dark, cold, hostile environment where food is scarce. With a fleshy filamentous growth on top of their heads that produces bioluminescence and acts as a lure, hanging above an impressive crescent-shaped mouth surrounded by fang-like teeth oriented inwards and a very mobile jaw, angler fish are able to attract and consume prey twice the size of their bodies.
This description can only be applied to females. Males are at least ten times smaller and not much more than a helpless pair of well developed testicles with a powerful gripping mouth and one purpose: to find a female. Once this is accomplished, the male bites the female, normally on the underside of the body, and never lets go. Through enzymatic activity, the tissues surrounding the bite and the male’s mouth are digested and the two bodies fuse, sometimes down to a bloodstream level. This way, the male receives nutrients and the female has a permanent sperm supply to fertilize her eggs. Depending on the species, an individual female can harbor anywhere between one and eight males, which is particularly efficient in an environment where finding a mate is the greatest challenge.
The list of unusual procreational methods successfully employed by organisms all across the planet can stretch far beyond these overly simplified accounts. So if you ever thought that reproduction is terrifying, for whatever reason, think again: at least you will never have to risk being eaten, either whole or parts of you, or stabbed, or forced to switch genders, or (thankfully!) become one with your partner for the rest of your days, all in the name of contributing to the next generation.
