The Top 5 Most Terrifyingly Gruesome Sex Acts in the Animal Kingdom

guest author image

Carin Bondar

Guest Author

  1. Drawing by Carin Bondar

It’s Halloween! A favorite time of year for ghosting, gore, and horrifying displays. What a perfect setting in which to discuss the grisly sex lives of animals – which are akin to your worst Halloween nightmares come true. As you peruse your options for the freakiest costume or exhibit, ponder some of the harsh realities faced by animals that are merely trying to pass on those genetic blueprints...

1. Love Darts

    1. While notions of Cupid’s arrow dot the romantic landscapes of the unassuming human, snails in search of a little love are instead faced with a literal arrow: a love dart. 
    2. content-1477934342-euhadra-quaesita.jpg
    3. The euhadra quaesita snail, which uses "love darts" to mate. Wikimedia Commons

    4. For some snail species, such structures have evolved specifically for the purpose of wounding and controlling mates during the process of sex. Think of it as an extra-genital weapon for the dominant and violent side of the hermaphroditic partner. Love darts are comprised of calcium or chitin, and come in diverse forms ranging from simple cone-shaped darts to massive structures with blades and teeth. 


2. Apophallation

Any guesses as to the direct, literal meaning of this unusual word? If you’ve been apophallated, this is unfortunate. It means that your sexual partner has chewed off your penis. Unfortunate indeed. Also rude.


The mating dance of two banana slugs. Banana slugs can lose their penis as a result of furious mating. This picture was taken in August 2003 in El Corte de Madera Creek Open Space Preserve in Northern California. Part of the Midpeninsula Regional Open Space District system. Wikimedia Commons

  1. 3. Functional necrophilia
  2. The act of necrophilia (i.e. having sex with a member of either the opposite or same sex despite the fact that such partner is deceased) is actually quite common across the animal kingdom, and especially so in birds and invertebrates.

  3. It is a perplexing phenomenon, and biologists often have a difficult time discerning the reasoning behind its occurrence. However, in at least one Amazonian frog species, there are clear biological advantages to engaging in sex with a lifeless corpse. It turns out that "frankenfrog brides" are actually able to create viable offspring!

  1. content-1477934678-dead.jpg
  2. Drawing by Carin Bondar


    1. 4. “Not tonight honey, I have a headache"
    2. "For real. I have a headache because you have repeatedly stabbed me in the forehead with your razor-sharp penis,” said members of an unnamed sea slug species living in the tropical oceans of the South Pacific.

    3. Although the exact mechanisms underlying this fascinating behavior have yet to be fully explained, biologists have discovered that the stabby sea slugs (a member of the Siphopteron genus) are delivering a dose of chemicals directly to the cerebral ganglion of their sexual partners. This neurochemical hijacking causes the receiving party to change its behavior in ways that benefit the perpetrator.

    4. SEM image of lateral view of a love dart of the land snail Monachoides vicinus. The scale bar is 500 ?m (0.5 mm). Wikimedia Commons


5. Self-castration and cannibalism

  1. Ok, this is actually two because I couldn’t decide which of these examples was worse.

    Castration: Male Tidarren spiders have very large genitals. So large, in fact, that hauling around their extra-big members is quite awkward (they have two penises, or pedipalps). So the twisting begins. They twist, twist, and twist some more, until their genitals are broken free from the body and the males are liberated from their encumbrance. Sweet relief! These males are now functional eunuchs, however sexual reproduction remains possible.

  2. Each pedipalp can be inserted into the genital opening of a female along with some sperm. If it gets lodged deeply enough into a female, the appendage can also act as a mating plug – preventing other males from mating with her. In addition, a male can spend some of his new-found energy (from being set free from the burden of his genitals) by guarding "his" female and making sure that the broken-off genitals remain exactly where he put them.

  3. Golden orb weaving spider. Stu's Images/Wikimedia Commons

Cannibalism: It’s perhaps the most severe kink in the animal kingdom when it comes to sex: eating your mate once the deed is done. But what about before it gets done? What if a girl simply finds herself in need of a little light lunch? Females of an orb-weaving spider species secrete a sticky substance from their genital opening that can be used to ensnare unsuspecting, love-sick suitors to their untimely deaths. Picture a life-sized sticky trap on your nether regions. For these ladies, it’s an indirect way of making sure they have a snack for later. 



I suppose that after having read through these rather horrifying examples of how animals have sex, you may find yourself asking a rather obvious question:  WHY? How come sex can be so violent, deadly, gory, and gross? I’ll invite you to click here to order your own copy of Wild Sex to find out…


  • tag
  • sex,

  • animals,

  • castration,

  • cannibalism,

  • Halloween,

  • necrophilia,

  • Apophallation,

  • Love Darts