Spiders

Basic Information

Spiders are not insects — they belong to a special group called arachnids, which have eight legs instead of six!

Scientists have discovered more than 52,000 different species of spiders around the world, and they think there might be thousands more we haven’t found yet!

A group of spiders is called a cluster or clutter, though most spiders prefer to live alone!

The smallest spider in the world, the Patu digua from Colombia, is smaller than the head of a pin — only 0.37 millimeters long!

The largest spider in the world by leg span is the Giant Huntsman Spider, which can reach up to 12 inches (30 centimeters) across — about the size of a dinner plate!

Female spiders are usually larger than male spiders and can live up to twice as long!

Baby spiders are called spiderlings, and they often ride on their mother’s back when they’re very young!

Some spiders can live up to 25 years in captivity, though most house spiders live for about 1–2 years in the wild!

Spiders have special organs called spinnerets that produce silk, which can be stronger than steel when comparing the same thickness!

Most spiders are carnivores, which means they eat other animals — usually insects and sometimes other spiders!

The word “spider” comes from the Old English word “spithra,” which means “spinner”!

Spiders have been around for more than 300 million years — that’s even before the dinosaurs!

Not all spiders build webs — some chase their prey, while others hide and ambush it!

A spider’s body is divided into two main parts: the cephalothorax (head and chest) and the abdomen!

Most spiders have eight simple eyes, though some cave-dwelling species have no eyes at all!

Spiders have special hairs on their legs that can detect vibrations in the air and on surfaces, helping them locate prey and avoid danger!

Physical Characteristics

Spiders have special hairs on their legs that can detect vibrations in the air and on surfaces, helping them locate prey and avoid danger!

A spider’s exoskeleton (cuticle) is made of a material called chitin, which is similar to your fingernails!

Jumping spiders can leap up to 50 times their own body length — that would be like a human jumping over a football field in one leap!

Spiders have blue blood because it contains a copper-based molecule called hemocyanin instead of the iron-based hemoglobin in human blood!

Most spiders have three or four pairs of spinnerets, each producing different types of silk for different purposes!

A spider’s fangs, called chelicerae, are hollow like tiny needles and inject venom into their prey!

Spider silk is stronger than steel and tougher than Kevlar! Scientists are studying it to create amazing new materials, from bulletproof vests to medical supplies, all thanks to its incredible strength and flexibility!

Some spiders can change color to match their surroundings, similar to chameleons!

The pressure inside a spider’s body is different from mammals — they move their legs by controlling fluid pressure, like tiny hydraulic machines!

Most spiders have tiny claws at the end of their feet that help them grip surfaces and walk on their webs!

Spider eyes come in different sizes and arrangements depending on their hunting style — jumping spiders have the best vision!

Male peacock spiders have colorful patterns on their bodies that they show off in special dances to attract females!

Some orb-weaver spiders can grow up to 1.1 inches (2.8 cm) in body length — about the size of your thumb!

The hairs on a spider’s body are so sensitive they can feel a fly’s wing beats from several inches away!

Spiders don’t have a skeleton inside their body — their hard outer shell provides support and protection!

A spider’s mouth is so small that it can’t swallow solid food — it has to liquefy its prey first!

Some spiders have special pads on their feet called scopulae that let them climb up smooth surfaces like glass!

The golden silk orb-weaver spider produces silk that appears golden yellow in sunlight!

Trapdoor spiders have extra-thick legs that help them hold their burrow door closed against predators!

Behavior & Intelligence

Some spiders can count — they keep track of how many prey items they’ve caught in their web!

Spiders clean themselves like cats do, using their legs to groom their bodies and keep their sensitive hairs working properly!

Mother wolf spiders carry their egg sac behind them and can tell if it’s been switched with another one!

Spiders can learn from experience — if they build a web that doesn’t catch many insects, they’ll try a different design!

Social spiders live in groups of up to 50,000 individuals and work together to build giant webs!

Some spiders play dead when threatened, remaining completely still until danger passes!

Orb-weaver spiders often eat their old web each morning and rebuild a new one, recycling the silk proteins!

Male spiders often bring “gifts” of wrapped prey to females before mating!

Some spiders can swim underwater by creating an air bubble around their body that works like a diving bell!

Bolas spiders catch moths by swinging a sticky blob of silk like a lasso!

Some spiders can walk on water using surface tension and special water-repelling hairs on their legs!

Some spiders take care of their babies for several weeks after they hatch, feeding them pre-digested food!

Jumping spiders can plan routes to reach their prey, even if it means temporarily moving away from their target!

Desert spiders can stay cool in the hot sun by digging burrows up to a foot deep!

Some spiders build decoy “spiders” in their webs using bits of debris to confuse predators!