47 Fun Facts About Spider

Spiders belong to which order?

Araneae are the true spiders; the look-alike harvestmen belong to a separate order, Opiliones, and give themselves away with a body in one piece, just two eyes and no silk.

Which is the only continent with no spiders?

Antarctica is the only continent with no spiders; elsewhere they reach even the high slopes of Mount Everest, where one tiny species hunts flies and springtails among the rocks.

Unlike insects, spiders lack which sensory feature on their heads?

Spiders have no antennae; insects smell and feel with antennae, while spiders rely on sensory hairs and slit organs spread over their legs and body.

How do spiders straighten their legs at the joints that have no extensor muscles?

Hydraulic pressure: muscles in the body squeeze blood into the legs to straighten them, which is why a dead spider's legs curl inward once the pressure is gone.

The spider genus Bagheera takes its name from a black panther in which children's classic?

The Jungle Book: the genus honours its panther and the species name kiplingi its author, although the spider itself turned out to live mostly on plant food.

By one 2017 estimate, roughly how much prey do the world's spiders kill each year?

400 to 800 million tons, over nine-tenths of it insects and springtails; where spiders were removed from test plots, insect numbers rose sharply.

In which property does dragline spider silk beat both steel and Kevlar?

Toughness means energy absorbed before breaking; silk's stretchiness is what makes it so hard to snap.

Darwin's bark spider, which lives beside rivers in Madagascar, holds what record?

Darwin's bark spider builds the largest orb webs ever found, slung across rivers on bridge lines up to 25 metres long with capture areas of up to about 2.8 square metres.

Which is the world's largest spider by mass and body length?

The Goliath birdeater, a tarantula of northern South America, can weigh about 175 grams; despite its name, it rarely eats birds.

Males of Patu digua, a Colombian contender for the world's smallest spider, measure about how long?

0.37 mm, well under the width of a pinhead; it is only a contender because a Samoan cousin, the moss spider, measures almost exactly the same.

Which is the largest spider family, with around 7,000 described species?

Salticidae, the jumping spiders, account for about 13% of all known spider species; they pounce on their prey instead of snaring it in a web.

Which jumping spider genus is famous for hunting other spiders and improvising its tactics?

Portia, a jumping spider that preys on other spiders, improvises tactics such as plucking a web to mimic struggling prey, and remembers which tricks worked.

The dancing peacock spiders of the genus Maratus are native to which country?

Peacock spiders are Australian; nearly all Maratus species live only in Australia, where males about 4 to 5 mm long raise coloured abdominal flaps and dance for females.

Which is the only spider known to live almost entirely underwater?

The diving bell spider lives in an air-filled silk bell among water plants; the bell works like a gill, drawing oxygen from the water, so it seldom has to surface.

Bolas spiders catch moths by doing what?

Swinging a sticky ball on a line: the spider swings its 'bolas' at male moths, which it draws within reach with a scent that mimics a female moth's.

What is the name for the way small spiders travel by releasing fine threads and riding the wind?

Ballooning: the spider lets out silk threads that are lifted by the wind and even by the atmosphere's electric field, and it can be carried hundreds of kilometres.

Which two spiders are the best known in North America for venom that can seriously harm people?

Brown recluse and black widow: the recluse's venom can destroy skin tissue around the bite, while the widow's is a nerve poison that brings on severe muscle pain and cramps.

The brown recluse is nicknamed for a mark shaped like which instrument?

Violin, hence 'fiddleback', though other spiders carry similar marks; the surer sign is its six eyes in three pairs, where most spiders have eight.

Black widows, redbacks and the New Zealand katipō all belong to which genus?

Latrodectus is the widow genus; its latrotoxin venom causes latrodectism, and its roughly three dozen species include South Africa's button spiders.

The Australian redback is one of a number of spiders that usually do what while mating?

Eat the male: during redback mating the male somersaults onto the female's fangs and is usually consumed, a sacrifice that lengthens copulation and raises his share of paternity.

Which Australian spider has killed no one since its antivenom arrived in 1981?

Sydney funnel-web: only the wandering males are known to have killed, and no death from a bite has been recorded since the antivenom came into use.

Number 16, the oldest spider on record when she died aged about 43, was what kind of spider?

A trapdoor spider: she spent her whole life in a single burrow, checked on by researchers from 1974, and beat a record held by a 28-year-old tarantula.

Many tarantulas of the Americas defend themselves by flicking what at an attacker?

Irritating hairs: the spider kicks them off its abdomen with its back legs, and they inflame an attacker's skin and eyes.

How do wolf spiders carry their egg sacs?

Attached to their spinnerets: the female holds the round sac clear of the ground at the tip of her abdomen, and once the young hatch they ride on her back.

The giant huntsman of Laos has the widest leg span of any spider; about how wide?

30 cm, about the length of a school ruler, although its body is under 5 cm long; the species was only described in 2001, from a cave.

Spiders of the family Uloboridae are unusual because they lack what?

Venom glands: these hackled orb-weavers make up for it by wrapping prey in so much silk that it is crushed.

A spider's gut is too narrow for solids, so what does it do to prey before feeding?

Floods it with digestive fluid: the spider vomits enzymes over or into its catch, then sucks the liquefied meal back up and discards the hard parts.

In Ovid's Metamorphoses, the weaver Arachne becomes a spider after challenging which goddess?

Minerva (Athena): in Ovid's telling the Lydian weaver Arachne matches the goddess in a weaving contest, is struck in fury and, after hanging herself, is turned into a spider.

In E. B. White's Charlotte's Web, what is the first message Charlotte weaves to save Wilbur?

'Some Pig' is the first message Charlotte weaves in the 1952 book; 'Terrific', 'Radiant' and 'Humble' follow, and her full name, Charlotte A. Cavatica, echoes the barn spider's Latin name.

Little Miss Muffet, frightened away by a spider, was eating what?

Curds and whey: the rhyme was first printed in 1805, and a popular but unproven story makes Miss Muffet the daughter of Thomas Muffet, a Tudor doctor who studied spiders.

Spiders' fangs are the final sections of which appendages?

Chelicerae are a spider's jaws: each has a stout base and a hinged fang that folds back against it like a pocket-knife blade, with a venom opening near the tip.

Which copper-based pigment carries oxygen in spider hemolymph?

Hemocyanin, a copper-containing protein dissolved in the hemolymph, carries oxygen in spiders; it turns faintly blue when oxygenated, unlike iron-based hemoglobin.

What are the sheet-like breathing organs found in tarantulas and other primitive spiders called?

Book lungs: stacked, leaf-like plates that exchange gases with the hemolymph; tarantulas and other mygalomorphs have two pairs, opening on the underside of the abdomen.

What is the narrow waist joining a spider's cephalothorax to its abdomen called?

The pedicel is the slim waist between a spider's two body parts; it lets the abdomen swing freely, which the spider needs when spinning silk or displaying to a mate.

The name 'tarantula' first belonged to which kind of spider, found around Taranto in southern Italy?

A wolf spider: its bite was blamed for a frenzy that only wild dancing, the tarantella, was thought to cure, and the name later passed to today's big hairy spiders.

Jumping spiders stalk and pounce instead of spinning webs; which sense do they mainly rely on?

Sight: their big front eyes give them some of the sharpest vision of any arthropod, good enough to judge the distance of a leap before they make it.

The world's heaviest tarantula warns off attackers with a loud hiss; how does it make the sound?

Rubbing its bristles together: stiff bristles on its legs and palps rasp against one another, a warning loud enough to be heard several paces away.

Spider silk genes were spliced into which farm animals, whose milk then carried the silk protein?

Goats: a Canadian firm bred them to secrete a gram or two of silk protein in each litre of milk, hoping to spin it into a fibre it called BioSteel.

Wolf spiders belong to which family, whose name comes from the Greek word for wolf?

Lycosidae, from the Greek for wolf, hunt alone and mostly without webs, running prey down, pouncing on it or ambushing from burrows.

Spiders belong to which class of animals, alongside scorpions, mites and ticks?

Arachnida is the class, and spiders are only one of its orders: every spider is an arachnid, but a scorpion or a tick is an arachnid without being a spider.

The mostly vegetarian spider Bagheera kiplingi feeds on nubs grown by which ant-guarded trees?

Acacias: the spider lives on the trees in Mexico and Central America and steals the protein-rich leaf-tip nubs they grow for the ants that guard them.

Which Northwest spider was once blamed for rotting wounds?

Hobo spider: case reports from the US Pacific Northwest tied it to rotting wounds, but no clear evidence followed, and experts no longer count its bite as medically important.

What is the especially fine silk that airborne spiders use to lift off called?

Gossamer is the especially fine silk spiders release to ride the wind; the word later came to mean any exceedingly fine thread or fabric.

What does a daddy-long-legs spider do when something disturbs its web?

Whirls rapidly: it shakes so fast in its web that it becomes a blur and a predator struggles to see it, which is why it is also called the vibrating spider.

The world's heaviest tarantula lacks which structure found on most adult males' front legs?

Tibial spurs: males of Theraphosa blondi lack the tibial hooks most male tarantulas use to hold off the female's fangs while mating; the species burrows in rainforests of the Guianas and northern Brazil.

What tells a fishing spider at the water's edge where its prey is?

Surface ripples: with its front legs resting on the water, the spider reads the waves a struggling insect makes, then runs out across the pond to seize it.

Daddy-long-legs spiders are rumoured to have the deadliest venom of all; what do tests show?

Weak, even on insects: the rumour probably began because these spindly spiders kill and eat redbacks, and their fangs can in fact pierce skin, leaving only a brief sting.