Don't you hate it when you accidentally have sex with your sister? This happens to Indian meal moths, a common kitchen pest that feeds on grains and cereals. Being moths, they don't really care about the moral issues, but offspring of an incestuous moth union are likely to be infertile. And since the moths have only a week get busy before heading off to the Great Pantry in the Sky, they can't afford too many reproductive dead ends.

But new research, published in this month's Animal Behavior, shows that male moths can stop worrying about fruitlessly spending their sperm on their sisters. Male Indian meal moths are tantric masters. If they're getting down with an unrelated lady friend, they give her ejaculate chock-filled with the very finest of sperm. But if they met their sweetie in the next cocoon over, they only release half as many sperm. That way, the moth isn't wasting energy on a whole Flowers in the Attic scene and can save his sperm for a less related lady.

While many female insects have a built-in morning-after pill that allows them to discard sperm they don't like, it was thought that male insects just had to thrust and think of England. But apparently even male moths yearn for control over the ultimate fate of their gametes. After all, when a single sperm can make the difference between being a grandpa moth or evolutionary roadkill, every sperm is indeed sacred.

Photograph of mating Indian Meal Moths by Richardus / Wikipedia.

Tags: family values, moths, Science, sex

It's tough to be a fuzzy little mammal. Death can come from the sky or beneath the earth or behind the next tree, so their lives are governed by constant, quivering fear. Prey species live in a dangerous neighborhood, and they must always be alert to their surroundings. That's why a Middle Eastern plan to control pest populations with predatory birds is brilliant. Instead of pouring toxins on their crops to kill rodents, they are installing nest boxes for day-hunting kestrels and night-hunting barn owls to provide around-the-clock mouse munching.

While the kestrels and owls certainly do kill rodents directly, their very presence means that pest populations are reduced before they even lift a claw. Without predators around, the mice and insects stuff themselves all day long without fear. But once the prey know that they could get chomped at any moment, fear changes their behavior completely. They hide more, eat less, and have fewer babies. Even if they can get enough food, the incredible stress of being ready to flee at any moment reduces their lifespan. Past studies have shown that grasshoppers are so afraid of wolf spiders that they will starve to death in hiding rather than seeking food near the spider. And rabbit babies born to parents who are afraid of lynxes are less healthy than rabbit babies born to parents in lynx-free environments.

Fear can also change entire ecosystems. When wolves were reintroduced to Yellowstone, the fat, lazy elk were forced to run away instead of spending their days lounging by the river. Once the elk stopped overgrazing, willow trees were able to regrow near the water, creating bird habitat. Now that the willows have regrown, beavers might come back and dam up parts of the river, making homes for fish and wading birds. The wolves are killing relatively few elk, but the behavior of the entire population has changed.

I hope more farmers put out owl and raptor nest boxes—I'd much rather have my veggies taste of fear than of pesticides. And while bringing top predators like wolves and mountain lions back into densely populated areas is probably impractical, I think the fear that would induce might have other benefits. Can't you envision the popularity of the "How To Lose Ten Pounds By Hiding From Ravenous Beasts" diet?

Photograph of mouse by John Foxx/Getty Images.

Tags: barn owls, grasshoppers, Israel, predators, rabbits, rodents, Science

Ever had the feeling that your male is getting restless? Think he's not ready to settle down with you and have 10,000 larvae and a white-picket mud burrow? If you've got a hard time finding a man, a dwarf male might be right for you. Dwarf males have evolved to be tiny semi-parasites, forgoing feeding and swimming for a life of providing you with sperm-on-demand. Since dwarfism makes a good man easy to find (there he is, stuck to your shell or living in your gut!), it's perfect for gals on the go. Here are three easy ways to keep your dwarf male with you for ever and ever:

Attach him to your hip. The deep sea anglerfish (as seen in that hallmark of marine biology, Finding Nemo) keeps six or seven males by her side—literally. Anglerfish spend their lives in the pitch-black water, luring prey to their doom with a little light dangling off their foreheads. When a male encounters a female, he bites into her side with his giant scraggly teeth and hangs on for the rest of his life. Eventually, his organs degenerate and his blood supply fuses with that of the female, leaving him to function as simply a scrotum. Sure, a scrotum might not be so good for conversation or long walks on the beach, but he's not going anywhere.

Choose a live-inside boyfriend. In the whale-bone eating worm Osedax, dwarf males inhabit the female's intestine. In this case, sex is determined by the environment—if a larva lands on a nice fresh whale skeleton, it turns into a female. But if a larva gets ingested by a female, it turns into a male and spends its life inside her gut with up to 100 harem-mates. As long as you don't get indigestion, he'll never leave you.

Make him give up a big something. If he won't permanently attach, there are still ways to make it hard for him to go anywhere. Amongst the free-living triangle spiders, the male body size has shrunk, but the female anatomy remains the same. In order to please their ladies, male triangle spiders have to drag around enormous, disproportionate male organs called "palps." Upon reaching adulthood, a male breaks off one of his two palps in order to be able to walk. The remaining palp is for you—and if you aren't pleased you can always tear it off and eat him.

Tags: animal behavior, marriage and commitment, sex

Whining is universal. From the frantic peeping of baby birds to the whimpering of a kid deprived of Chocolate Frosted Sugar Bombs in the supermarket checkout line, young critters know how to get their parents to feed them. Crying or squeaking or mewing tells the baby's caretaker that they have needs that must be met NOW!!! But in the case of the European earwig, begging is a fatal miscalculation. Whiny earwig babies don't get sent to their earwiggy rooms—they get starved to death by their mothers.

European earwigs, easily recognized by the giant pinchers adorning their buttocks, are a common garden pest that eats other insects, plants, and fruit. Despite their crawly appearance, female earwigs are good mommies, taking care of their 50-100 babies by feeding them regurgitated glop. Baby earwigs, called "nymphs," don't make sounds, but they do signal their hunger with chemical signals.

To figure out how the mother earwig responds to her offsprings' hunger, researchers ground up well-fed nymphs and poorly-fed nymphs, extracted the oils from their bodies with solvent, and dosed intact earwig nests with eau de baby. They found that nymphs treated with the happy-baby smell got fed, while nymphs treated with the sad-baby smell were ignored. Mother earwigs concentrated their efforts on the least needy babies, while the nymphs that smelled like whining were left to starve.

Despite its cruelty, this makes evolutionary sense for animals with lots of babies that aren't expected to live to adulthood. Why spend your time feeding whimpering weaklings when you could prepare your very best offspring to be all they can be? Unfortunately for people stuck on airplanes with whining Homo sapiens offspring, evolution dictates that species that invest a lot in a single baby have to take better care of it. Still, don't you think the "Tale of the Begging Earwig" would make a great bedtime story?

Image by Menchi/Wikimedia

Tags: evolution, insects, motherhood, whining

The hoary old evolutionary explanation for gender differences is that males are slutty and females are choosy. Males sleep around in order to fertilize as many eggs as possible, while females guard their virtue until Prince Charming comes along. But with the advent of genetic techniques (and in my opinion, female biologists), scientists have found that nature overflows with wanton females. Figuring out evolutionary reasons for looseness in ladies is harder—since each egg can only be fertilized once, having lots of sex won't necessarily lead to more babies. A study on a European songbird, published in last month's Current Biology, reveals one possible reason for female infidelity—bastard chicks are bigger and stronger than their legit half-siblings.

The delighfully named blue tit (scientific name: Cyanistes caeruleus) is a common European songbird with a common songbird lifestyle—they mate for a season, the male defends his territory with song, and the female lays and incubates the eggs. But over 40 percent of the female blue tits are getting around all over blue tit town, cuckolding their mates right and left. When researchers examined the fate of chicks sired in and out of wedlock, they found that the illegitimate chicks were healthier because they were laid and hatched sooner, therefore getting more food and attention than the later-born chicks. If chicks born of cheating hatch earlier, survive better, and live to pass on mama's ways, no wonder female blue tits can't keep it in the nest.

The bastard advantage in blue tits is yet another demonstration that the natural world does not conform to conservative talking points. In fact, all that finger-shaking on premarital sex hurting women's ability to bond with future partners was based on research on the prairie vole. Thought to be a paragon of monogamy, those naughty, bad rodents were caught cheating on their partners-for-life last year. The free-flying blue tit lifestyle is no more unusual than living in a harem or inside your sweetie's intestine—it's monogamy that's hard to find.

Photograph of Blue Tit by Luc Viatour/Wikipedia

Tags: birds, conservatives, evolution, gender roles, sex

It never fails. Every single cocktail party, as soon as someone finds out that I'm a graduate student studying marine biology, they ask, "So, do you get to play with dolphins?" Since my heart is as black and cold as the oceanic abyss, I usually take this opportunity to disillusion yet another poor soul of their childhood fantasy of Mystical Dolphin Love.

Dolphins are not gentle or psychic. If they could talk they would not impart eco-wisdom or deep spiritual truth. Dolphins are violent predators with a predilection for baby killing and rape. I feel it's my duty to warn you, despite the risk of insulting creatures made of hundreds of pounds of muscle and rows of sharp teeth. Throw out your rainbow dolphin painting, and check out dolphins' low-down dirty secrets:

--Dolphin sex can be violent and coercive. Gangs of two or three male bottlenose dolphins isolate a single female from the pod and forcibly mate with her, sometimes for weeks at a time. To keep her in line, they make aggressive noises, threatening movements, and even smack her around with their tails. And if she tries to swim away, they chase her down. Horny dolphins have also been known to target human swimmers—Demi Moore is rumored to have had a close encounter of the finny kind.

--Dolphins kill harbor porpoise babies. In Scotland, scientists found baby harbor porpoises washed up with horrific internal injuries. They thought the porpoises might have been killed by weapons tests until they found the toothmarks. Later, dolphins were caught on film pulping the baby porpoises—the dolphins even used their ecolocation to aim their blow at the porpoises' vital organs.

--Dolphins kill their own babies. Baby dolphins have washed up alongside the dead porpoises, and some scientists think that all the porpoise-slaughter was just practice for some old-fashioned infanticide. For other mammals like lions, killing the babies makes the females immediately ready for the next pregnancy, and maybe that's the case with dolphins, too.

The scariest part is dolphins can wreak havoc day and night without sleeping. A recent study found that dolphins could stay awake for five days straight with no loss of mental acuity. The dolphins didn't even need to make up sleep at the end of the study, though the scientists sure did.

If the dolphins ever evolve thumbs, we're in trouble. It will be like a slasher-film remake of Douglas Adams' So Long And Thanks for All The Fish. If I wash up with pulped innards and dolphin tooth marks, you'll know why. After all, you never hear about the people the dolphins push out to sea.

Tags: animal behavior, dolphins, marine biology