STEPHEN FRINK COLLECTION/ALAMY STOCK PHOTO / sciencemag.org

To a lobster couple, this is normal sex: For days the female squirts urine into the den of her desired mate. Beguiled by the scent, he lets her move in. – TinyFoxLab

Source: National Geographic, Preview photo credit: STEPHEN FRINK COLLECTION/ALAMY STOCK PHOTO / sciencemag.org