Homo sapiens aren't the only species on the planet that engages in deception for sexual gain. There are several animals that trick their mates, ranging from insects to antelope. Surprisingly, a lot of this deception involves males disguising themselves as females, meaning Shakespeare might have known just as much about the nature of animals as he did about man.
Other animals with manipulative mating strategies use pheromones, false alarms, and even a form of blackmail to seal the deal. Using human standards, the guys on this list - and yes, they're all male - are reprehensible. But to paraphrase Hamlet, what separates us from the beasts is our "godlike reason" that tells us, among other things, that tricking people into sex is best left to "bestial oblivion."
You know you're desperate to hook up when you literally evolve into a permanent different version of yourself in order to fool the opposite sex into letting you get close to them.
That's exactly what a tiny percentage of male ruffs, a wading sandpiper bird, have done. Genetically unusual "female mimic" ruffs wait until an actual female presents her cloaca (genital opening) to an aggressive, "regular" male going through an elaborate mating ritual. That's when the mimic, looking like a female but slightly larger, sneaks in between them and fertilizes the female. Since the mimic also has larger testes than ordinary males, they have more reproductive success over a lifetime, but at a cost: the resulting offspring doesn't survive nearly as often as one from a "normal" pairing.
The illustration above shows a "regular" male ruff on the right and a female on the left, but female mimics, naturally, look essentially the same as the true females.
Perhaps the most despicable example of sexual trickery in the wild is that of the male water strider, the zippy little bug you see walking on water at your local lake or pond.
This guy skips courtship rituals and foreplay altogether and cuts right to the chase. Sometimes, the female resists, prompting the male to threaten the female in an extraordinarily cowardly way: he strums the surface of the water with his legs to attract the attention of the predatory backswimmer, an insect that swims just under the surface. If the female doesn't give in, the strumming summons the predator to attack the female, who is held in place by the male. It's a revolting display of sexual blackmail, but the females have one form of protection: they can block their vaginas with "hard genital shields."
If small male spear squids were human beings, they'd be the sleaziest dudes on the planet. Not only do they lie in wait and watch other squids get it on, they also sneak in later and mate with the female trying to lay her eggs from the first go-around.
What's complicated is that the female "consents" to this behavior, so to speak. It's more than just consent, actually: biologically, they are equipped with a "sperm storage organ" near their mouths (don't ask) that's specifically for the sneaky spear squid's sperm. The larger males still dominate, but this peculiar arrangement means the smaller males still have a slim chance to father some offspring.
Male animals disguising themselves as the opposite sex for sex isn't that uncommon, but the Giant Australian Cuttlefish takes things to the next level.
The cuttlefish dating scene is a fierce, highly competitive undersea sausage fest, with up to 11 males competing for the attention of one surely exhausted female. Whenever one of these males "wins" the female, they like to guard her. That's when the deception starts: to sneak by the guardian, a cuttlefish can instantaneously change its coloring to look more female, hide a few of its eight arms, and even change the shape of its visible arms to adopt a convincing female look in mere seconds.