“Evolution, what are those flatworms doing?”

“Oh, they’re getting ready to penis-fence.”

“Penis… fence?”

“Yeah. They’re hermaphrodites, so either of them can inseminate the other one to reproduce, but neither one actually wants to be inseminated.”

“They… don’t?”

“Well, no. It’s much easier to be the inseminator. I kind of set it up so that actually bearing the offspring totally sucks. Haha, whoops!”

“So… they’re going to…”

“Try to stab each other with their two-pronged penises while simultaneously avoiding getting stabbed themselves, yes.”

“Jesus.”

“The good news is that there’s no real reproductive opening, so they can just pierce the skin wherever and get the sperm in.”

“That’s the good news?”

“Well, I thought so. Ooh, they’re starting! Fatherhood to the victor!”

“It is way too early in the morning for this.”

Source: Wikimedia Commons / Photo courtesy of Nico Michiels / licensed under CC BY 2.5

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