No self-respecting haunted house can operate without them. Their image exerts a visceral power; our revulsion is automatic. When we want to make the skin crawl, we know what to do. Trot out the spiders.

After decades of attempts to intellectualize my way out of it, I’m still a card-carrying arachnophobe. The spider is a creature grotesquely unlike me. It sports eight legs and way too many eyes for my taste. It wears its skeleton on its sleeve and its abdomen in its back pocket. And it dines with a gruesome gentility, paralyzing its prey with venom, wrapping the hapless victim in silk while its innards liquefy, and returning later to sip away with a straw. No writer of horror fiction has dreamed up a beast more bizarre.

The Nightmare on Arachnid Street might feel like a primal emotion, but some experts aren’t so sure. Recent studies suggest that our disgust at the image of a spider is a form of disease-avoidance response with historical and geographical roots. When plague swept through Europe during the Middle Ages, spiders came to be associated with the plague. The real culprits were certain rat-infesting fleas, a fact not established until the 19th century. But in a house struck down by plague, the spider’s proximity to the rat made it a prime candidate for blame. (Spiders often hung out in areas of the house, such as the thatched roof, also occupied by rats.) Fear of the plague clouded people’s judgment, and their natural aversion to spiders – at first no greater than to other crawling things – soon went haywire.

In short, arachnophobia got its start as a “displaced anxiety” and became entrenched as an unconscious vestige of that anxiety. To augment this theory, researcher Graham C.L. Davey of City University, London points out that “the tendency of Europeans and their descendants to be fearful of spiders does not seem to be shared by people in many non-European cultures.” In fact, many non-European cultures revere spiders as symbols of wisdom or good fortune. Prominent in the folktales of the Ashanti of Ghana, West Africa is the character Anansi the Spider, a lovable trickster similar to the god Loki in Norse mythology.

In some parts of Africa, as well as Indo-China, the Caribbean, and among Native Americans and the aborigines of Australia, spiders are kept as pets, released at weddings as a token of good luck (and lovingly laid in the bed of the blissed-out couple), and even gobbled down (we’re talking lethally venomous spiders here) as a culinary delicacy. Mmmm.

One spider that inspires fear way out of proportion to its actual menace is the tarantula: huge, hairy, scary – and gentle as a lamb … unless you’re an insect.

The male tarantula stops growing at about age 7, at which time he sheds his exoskeleton for the last time. Normally a nocturnal creature, the mature male leaves the protection of his burrow in September and October and goes looking for a mate in broad daylight. That procreative impulse is good for the species but hazardous to the suitor’s health. Out in the open, the male tarantula becomes vulnerable to his chief nemesis, a wasp known as the tarantula hawk.

He must also contend with none other than the hungry female tarantula. A female will kill and eat the male after mating with him if she’s famished and he’s unable to vacate the premises post-haste. To prevent the female from enjoying him a little too well, the male grows two small frontal “stirrups” with which he hooks and neutralizes the female’s fangs before mating. After luring the female out of her burrow and impregnating her, the male never returns to his own burrow. He puts his nose to the reproductive grindstone and continues cruising for chicks until the lethal winds of November permanently end his quest.

If you’re camping or backpacking when male tarantulas are out in force, resist the urge to freak out – or lash out. Simply zip your sleeping bag nice and tight. And if a tarantula crashes your slumber party, don’t panic. He’s just looking for a warm spot to spend the night. Escort him out gently.

Those fortunate enough to cross paths with one of these remarkable guys should keep in mind that Mr. T leads a hard life. Admire, take your snapshots, but cut him some slack. Unlike those creepy-crawlies infesting our haunted houses, he’s probably just minding his own besotted business.