14 Most Fascinating Facts About Spiders

When a spider's web becomes too dirty or loses its stickiness, the spider often consumes the old web and repurposes the nutrients to build a new one. It’s a form of recycling, done the spider way.

A spider's web is a structure created from silk produced by the spider, known as spider silk. Typically, a web serves as a trap to catch prey that inadvertently gets stuck in it. Many spider species create elaborate webs specifically designed to capture insects. However, not all spiders catch prey in this way, and some species don’t use webs at all. Web-building spiders find a balance between running and spinning webs as part of their feeding habits.

There is a species of spider known as the 'Diving Bell Spider' that has adapted to life underwater. Its body is surrounded by a special layer of soft hairs that form air bubbles, providing it with oxygen in this unique habitat.

This spider is the only species that spends most of its time underwater, for activities such as resting, hunting, feeding, mating, and laying eggs. It only surfaces for air and occasionally brings prey to land. It thrives in clean freshwater environments with aquatic plants, such as lakes, ponds, marshes, and slow-moving streams. This spider is found across much of continental Europe, the British Isles, and northern Asia.

Other spider species are semi-aquatic. For example, some spiders in the genus Desis take shelter in air-filled silk sacs underwater during high tide and search for food in intertidal zones during low tide. Some spiders that live in flooded areas can survive for extended periods underwater by entering a state resembling hibernation.

Antarctica is devoid of any terrestrial spiders. The extreme cold temperatures prevent them from carrying out their normal metabolic processes.

However, sea spiders are incredibly abundant in Antarctica. With their long legs and proportionate proboscis, the giant sea spiders found in the region grow larger than any other spider species across the globe. These sea spiders belong to the marine arthropod class and can be found all over the Earth. While sea spiders elsewhere are generally small, those in Antarctica can have leg spans reaching up to 25 cm.

A group of American researchers hypothesized that the large size of Antarctic sea spiders is due to the high levels of dissolved oxygen in the cold water. The combination of high oxygen levels and slow metabolic rates in cold temperatures allows these sea spiders to grow to extraordinary sizes. Scientists collected specimens from the Antarctic seafloor, where temperatures range from -1.5 to -1.8 ºC, and tested them in varying oxygen conditions. The results supported their hypothesis that low oxygen levels adversely affect these creatures.

The Bagheera Kiplingi spider, discovered in the 1800s, primarily feeds on acacia tree shoots and plants. Occasionally, this spider also consumes larvae. It is the only known herbivorous spider in the world.

Named after the black panther from Rudyard Kipling’s "The Jungle Book," this species is the only one on Earth that subsists solely on plants. The Bagheera Kiplingi was first identified in the early 19th century.

These spiders primarily live on acacia trees and feed on a substance called Beltian bodies, which are rich in protein. Male Bagheera Kiplingi spiders are also known to help care for their eggs and spiderlings, a behavior that is unprecedented in the spider world. They are fast and skilled jumpers.

To truly understand spiders, one must delve into their anatomy and characteristics. Spiders belong to the arthropod class, which includes other creatures like ticks and scorpions. They lack a backbone, jaws, and have a body divided into two parts with eight legs. The entire structure of these predatory animals has evolved to help them combat larger creatures, hunt, and eliminate other invertebrates. Professor Chris Buddle from McGill University in Canada has stated, “Out of nearly 40,000 spider species worldwide, only about 10 can pose a threat to humans. Even venomous species rarely come into contact with humans, let alone attack us.”

Scientists have demonstrated that spiders do not bite humans through various experiments involving volunteers. In these tests, spiders and humans were placed in the same environment and allowed to interact freely. In the end, no volunteers were bitten. In another experiment, when spiders were placed with beetles, they detected vibrations in the environment and attacked. Therefore, a spider will only bite if it feels threatened through close contact, which usually happens when we unintentionally provoke them.

While most spiders pose no threat to humans, there are a few species whose venomous bites can be life-threatening. The Australian Redback Spider delivers a neurotoxic venom that can damage the human nervous system within 24 hours. The infamous Black Widow Spider also has a potent bite that affects the nervous system, but it's rarely fatal. The Brown Recluse's bite can lead to infection, blood poisoning, and necrosis. The large Tarantula found in tropical rainforests causes immediate unconsciousness in humans. The Six-Eyed Sand Spider's bite causes localized clotting and necrosis of the wound.

Without proper knowledge, people may confuse spider bites with those from other insects such as fleas, ticks, bedbugs, or mosquitoes. Skin reactions can also occur due to exposure to chemicals or toxic plants. Because symptoms vary widely, it is essential to take precautions when encountering spiders or insects in the wild.

The Black Widow spider often weaves large webs, where it hangs an egg sac and hundreds of eggs. Once the spiderlings hatch, they immediately leave the sac, and the mother uses the web to capture prey. As mentioned earlier, the Black Widow feeds on flies, mosquitoes, grasshoppers, beetles, and caterpillars...

The Black Widow spider has specialized hairs on its back legs that it uses to trap its prey in the web. These hairs quickly pierce the victim’s body and inject digestive enzymes that liquefy its tissues. This allows the spider to suck up the nutrients from the dissolved body of the prey.

Most insects have three main body parts: the head, thorax, and abdomen. Spiders, however, are different as they have only two: the fused head-thorax and the abdomen. At the end of the head-thorax, there is a connector that allows the spider to move its abdomen in all directions.

Spiders possess four pairs of legs attached to the head-thorax. Their bodies and legs are covered with fine hairs that help them detect vibrations, sounds, and scents. Each side of their mouth has fangs for gripping prey and holding onto mates during reproduction. Unlike many animals, spiders do not chew; instead, they extend a tube to suck out the liquefied contents of their prey.

Spiders generally have simple eyes, and their vision varies by species. Some can only distinguish light from dark, while others have vision nearly as sharp as birds. Most spiders have eight eyes, but species like Haplogynae have six, Tetrablemma have four, and Caponiidae have two. Some spiders have two eyes that are larger than the rest, while others may have no eyes at all.

Spiders typically have eight eyes, arranged in various patterns. This eye arrangement is often used to classify different spider species.

Spiders hunt and capture their prey, which primarily consists of insects and other invertebrates. Some of the larger spider species can even hunt vertebrates, such as birds. The Araneae order includes the largest predatory spiders on Earth.

Spiders use venom to subdue their prey. Venom glands are located near the fangs, connected by ducts. When a spider bites its prey, muscles around the venom glands force the venom through the fangs into the victim's body. Most venomous spiders paralyze their prey, although the Uloboridae family is an exception as they lack venom glands.

While most people associate spiders with web-building, some species don't spin webs at all. For example, wolf spiders actively hunt and chase their prey without relying on webs. Jumping spiders, known for their excellent vision and quick movements, also do not build webs. Instead, they simply pounce on their prey!

Other spiders don't use webs to capture prey directly. Instead, they may ambush from a hideout, like the trapdoor spider, or chase prey in an open pursuit, like the wolf spider. These spiders create small webs attached to their front legs, waiting in ambush. When a potential victim approaches, they lunge, entangle it in the web, and deliver a paralyzing bite. This method of hunting is less energy-consuming compared to the web-building strategy, as it avoids the need for spinning large webs. Some spiders even create strands of silk that catch the wind, allowing them to travel to new locations.

It may sound strange, but spiders don't actually have blood in the same way humans do. What they have is a fluid called 'hemolymph.' While human blood is red due to the iron-containing hemoglobin molecule, spider hemolymph uses a protein called hemocyanin, which contains copper. This substance is naturally clear, but when it binds with oxygen, it turns a blue color.

Before a spider can consume its prey, it must first liquefy the meal. The spider releases digestive enzymes from its stomach into the victim's body. These enzymes break down the tissues, turning the prey's body into a soft, liquid form, which the spider then sucks up along with the digestive fluids. The liquid meal is then transported to the spider's gut for nutrient absorption.

Some species actively lure prey and can catch it using a sticky silk ball, while others wait in ambush at areas frequented by prey, attacking directly from hiding.

When a prey item becomes trapped in the web, the spider immediately acts:

• It grabs the prey and injects venom
• Secretes digestive fluids into the prey's body
• Binds the prey and hangs it in the web for a while
• Drinks the liquefied contents of the prey

Spiders don't just rely on muscles to move; they also control their blood pressure to walk or jump, depending on the species. By contracting muscles in the cephalothorax, they increase the hemolymph pressure in their legs, which helps extend their movement range. This sudden increase in pressure allows their legs to jump in various directions.

Spiders combine muscle contractions with blood pressure (hemolymph) compression to move their legs. Some joints in their legs lack muscles for full extension. By tightening muscles in the cephalothorax, a spider can increase blood pressure in its legs and effectively extend them at the joints.

Spiders lack a backbone. Instead, they have a tough exoskeleton that surrounds their organs and blood. This feature places them in the category of invertebrates—animals without a spine. However, spiders are not the only creatures with an exoskeleton.

In fact, all insects and arachnids have this hard outer shell. Having an exoskeleton allows these creatures to grow, but it also means they must periodically molt or shed their outer layer. During this time, they can regrow their bodies in a short span. All invertebrates, including spiders, are particularly vulnerable until their exoskeleton hardens again.