Free Women After All: Sex, Evolution, and the End of Male Supremacy by Melvin Konner

mushrooms. The silk she spins is lighter but stronger than steel wire of the same thickness. Her venom, much stronger than a rattlesnake’s, can kill a human child; it routinely kills a broad spectrum of insect prey and, by the way, the black widow male. She is solitary and shy the year round, except for this rather harsh mating ritual. She weighs thirty times what he does, so it’s not exactly a contest.
    But it is a courtship. Think of a powerful Amazon queen who has won the heart of a Lilliputian. He steps gingerly onto her web and taps the strands, much like the water striders we encountered earlier, but here it’s the males’ tapping that sends out a song of love—or lust, at least—in patterned vibrations. If she is suitably moved, sheallows him closer. She lets him climb her great body, where he continues to woo with fancy stepping. He places his sperm inside her with a special feeler, which breaks off after he makes his deposit; he’ll be a lucky boy if that’s the only body part he leaves behind.
    Sometimes the hourglass seems to mean his time is running out, but it’s just part of her siren song. If it’s not his lucky day, she grabs, stings, and wraps him just as she would a mosquito, injects the tidy package with digestive enzymes that turn him into a rich broth, and drinks him down. Aided in part by this delicious, nutritious meal, the widow soon lays a silky, liquid sac bulging with two hundred eggs and weaves a blanket around them, wrapping them neatly and attaching the cocoon to her web. She does this five more times with eggs fertilized by that one brave or crazy male, and in two weeks there are a thousand new baby black widows.
    In a 2012 study of a closely related spider, the orb weaver, Klaas Welke and Jutta Schneider found that females prevented from eating their mates had fewer, smaller eggs that survived less well under stress. This is also true of female tarantulas, although if they have already mated once, they may lure a few more males and eat them one by one without even letting them have their sexy moment in the sun. Scientists drily note that tarantula females are “nutrient-limited” and “males are high-quality prey.” Another study of orb weavers, called “Safer Sex with Feeding Females,” showed that males have evolved ways to try to avoid being eaten, but only some succeed.
    Female praying mantises have their own charms and slightly different sexual appetites. Some say the males must be praying that they will survive sex (and they do try to survive), but females, if hungry, just seem to pray for their next male meal. Female mantises are world-class hunters that can kill and eat mice, snakes, and hummingbirds bigger than they are. The female can and often does eat the male after sex, but she doesn’t have to wait until he’s finished. She can start by biting off his head while he is at it, and (typical male) his decapitated body can go right on with the show. If it sometimesseems that men don’t need their brains to have sex, consider the praying mantis male. Talk about a boy losing his head over a girl.
    Probably the most complex animal with sexual cannibalism is the octopus. One female lingered outside her den near a Pacific coral reef as a small male mated with her thirteen times in four hours. Octopus males can have an intimate encounter or they can mate at a safe distance, depositing sperm with one of their arms; this male kept his distance throughout. Often he jumped back a few feet, sensing danger. Five times, “she showed only a subtle head bob and a faint darkening of her body pattern. On five occasions, the male blanched white briefly,” a sign of fear, yet cautiously came on again.
    Thirteen was not his lucky number. Shortly after the last mating attempt—it’s not clear whether he actually deposited sperm—she sidled up and forcefully swatted him off a ledge of coral. He released abundant ink in defense. “She quickly pounced and engulfed him in her arms”