Mary Roach’s book "Packing for Mars: The Curious Science of Life in the Void" explores the challenges of reduced-gravity sex, using sea otters as a case study. During mating, male otters face significant difficulties, as they must physically restrain the female by pulling her head back and gripping her nose with their teeth. This behavior has resulted in injuries requiring surgical repairs, specifically rhinoplasty, for some female otters, highlighting the complexities of their reproductive rituals.

Additionally, the mating experience can be perilous for male otters, who are often subjected to relentless attacks from sea gulls. These birds misinterpret the male's erect penis as food, leading to aerial assaults that complicate the process even further. Roach’s examination of these unique challenges sheds light on how gravity—or the lack thereof—affects not only human interactions but also those in the animal kingdom.