We found out ancient fish in Scotland may have invented sex.

The first animals to reproduce through genital mashing were small fish that lived about 350 million years ago, a paper published in Nature shows. While their ancestors laid boring-old eggs, the aptly called Microbrachius dicki had sex side-by-side, linking fins so they wouldn't float apart. Aww!

vine.co / Via nature.com

And that the larger a narwhal's tusk, the bigger their balls.

Because they're such elusive creatures, scientists weren't too sure about their mating habits or what those tusks are for exactly.

But new research published in Marine Mammal Science this year shows male tusks can be indicators of their testicle size — an indicator of fertility. (Female narwhals have tusks too, but they’re smaller in size.) So ladies, the next time you see a big tusk... *winks*.

Via freedomforwhales.tumblr.com

Your eye movements can indicate whether you feel love or lust.

A study published in Psychological Science found that people's visual patterns concentrated more on a stranger’s face if the viewer saw the person as potential for romance. When the images made participants lusty, their gaze tended to look more at the person’s body.

Before you say “duh,” the automatic judgment can occur in as little as half a second, so it might not be perceivable.

Disney / Via disney.wikia.com