Weird & Wild: Five Ways Animals Get Creative About Sex

Curious about slugs with erections bigger than human ones? Or penis fencing? I was too. As much as I enjoy studying human sexuality, I am fascinated by what other animals in our wonderful world get up to when it comes to their sex & mating lives. Today, guest blogger David Manly teaches us a few things about how animals mate in the most interesting of ways. Enjoy. (Thanks, David!). – Debby


So, you are probably asking yourselves, why am I here?  And I don’t mean it in a philosophical sense, referring to your place in this universe.  But why am I, the writer, here on this blog talking to you? Simply put, I have a degree in Zoology, love everything about all different types of animals, and Dr. Deb asked me to share some thoughts and interesting things with you folks about animals.

Animals have been around much, much longer than us, and will most likely persist long after we are gone. So, animals are the true senseis of sex. They’ve been doing it longer, and are far better at it than we could ever be (yes, even better than the fabled Wilt Chamberlain).

And now, on to the main event!

I have combed through everything I have ever learnt about animals, and I have come up with a list of the 5 most bizarre, yet still interesting, animal mating strategies. Now, this is by no means a complete list, just the weirdest and most interesting. Believe me, there is a LOT more.  If you like it, I’m sure I could be persuaded to write more.

banana slugs mating

5) Banana slugs – Well, it IS stuck

Banana slugs look exactly as their name suggests, a slug the colour of a banana.  The interesting thing about these guys is that since they are hermaphrodites, when mating time arises, they both possess female and male sex organs.

And for your information, the average eight inch slug will have an eight inch penis when fully engorged.

Yeah, you read that right, it’s as big as they are.

Now, why are they on the list, other than their large penises?

Well, sometimes, after mating, the penis will get stuck if the mating pair are not similar in size.  So, to resolve the conflict, they will engage in a bit of post-coital biting.  But, unlike people, the biting isn’t playful.

One slug will literally CHEW off the penis of another.  They will bite, chew and eat the opposing snail’s penis until it is gone.  Does it grow back? Up to a year later, the answer is no.

For all you interested, here is a site where you can watch the process (Link).

snails penis

4) Snails – Darts, anyone?

Yeah, I know. First slugs, now snails, but there is a reason they are on the list.

First, they are hermaphrodites. Second, their genitalia are on their necks behind their eyes.

But the weirdest of all is called a “love dart.” See the red circle on the picture?  That is it, piercing the other snail’s neck.  It is like being jabbed in the throat with a hypodermic needle … one that is filled with sperm.

The darts are made of calcium, and coated with mucus before being fired.  Scientists used to think that it was a “copulatory gift” to entice the female to mate, but now believe that the mucus allows increased sperm survival in the acting female, thereby increasing the males chance of creating offspring.

porcupine sex and mating

3) Porcupines – I can taste the bubbles

How do you entice a female covered with deadly quills to mate with you?  Isn’t it obvious?

Shower her with urine!

In order to impress a female, a male porcupine will approach and stand up to six feet away.  He then showers her with a stream of urine and drenches her.  If she is impressed, she will let him mate with her.  If not, she will shake off the urine and walk away.

If accepted, the female will expose her quill-free behind, and let him mount her.  She will then force the male to mate numerous times until he is exhausted, or will seek out a more viable mate.

flatworm penis fencing

2) Flatworms – The lost art of fencing

Once again, hermaphrodites take the spot, as they have some of the weirdest mating rituals.

Flatworms are fairly simple creatures, but when its time to mate, the individuals fight for the right to mate. Except, they don’t use swords, they resort to “penis fencing.”

Like fencing, the flatworms duck and dodge their opponent’s sword while trying to perform the coup-de-gras on the opponent.  The ‘winner’ is the first one to stab the other with their penis.  In doing so, they release sperm onto the loser’s skin.

The sperm is absorbed through the skin, and the loser is thereby relegated to bear the biological burden of motherhood.

For all you curious people out there, here’s a link to a video of penis fencing (Link).

Picture 26

1) Anglerfish – I am SO into you

Let’s face facts, some guys are clingy.  Granted, there are different levels of clingy-ness.  But NONE hold a candle to the male anglerfish.

Originally, scientists never found a male anglerfish. But, scientists found a bizarre lump on the female that resembled a parasite.  It was discovered that it was the remains of the male.


Basically, the male anglerfish is much, much smaller than the female, and lacks a digestive system.  Therefore, when it is born, it needs to find a female fast.

When it does, it bites her, and secretes a digestive enzyme that digests her body and literally FUSES them together.

The male then becomes a parasite on the female, and almost completely disappears until he is nothing more than a lump with testicles.

But, when it’s time to mate, he releases sperm and fertilizes her eggs.

David Manly got his Honours degree in Biology/Zoology from York University in Canada, and did a thesis on salt tolerance in frogs.  He takes great pride in learning as much as he possibly can about the weird and interesting goings on in the animal kingdom.  His favourite animals are: Snakes, wolves and sharks.

David is currently at Carleton University getting his Master’s in Journalism with hope to write for a scientific publication such as Nature or Science. You can follow all his clever observations and animal facts via Twitter (@davidmanly) and his blog, entitled “Musings of a Manly“.

About Dr. Debby Herbenick

Dr. Debby Herbenick

Dr. Debby Herbenick is a sex researcher at Indiana University, sexual health educator at The Kinsey Institute, columnist, and author of five books about sex and love. Learn more about her work at