10 Amazing Things About Spiders By analise.dubner [230 more lists]

Most everyone hates and fears spiders on sight, but they are actually some of the most impressive, well-equipped animals on earth. They are the highest order of predator, built for killing and built for survival. Their amazing adaptive bodies make them some of the most successful carnivores on the planet. Over the past 400 Million years, they've managed to cover every continent and every environment. There are 40,000 known species and probably many more we've never even seen. It is estimated that there are up to 1 million spiders per acre of land on earth, and in the tropics, that number is thought to be closer to 3 million. That's a lot of spiders. Below are some of the more interesting facts about spiders. If you enjoyed this list make sure to check out my ant facts and most intelligent animals lists.

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1

Insect Control

Spiders eat more insects than birds and bats combined, so they should be considered one of human's best friends. They play a big role in controlling insect populations.
2

Spider Silk

Spider silk is incredibly strong and flexible. Some varieties are five times as strong as an equal mass of steel and twice as strong as an equal mass of Kevlar. This has attracted the attention of scientists in a number of applied science fields, but up until recently, humans haven't been able to get much out of this natural resource. It's simply too hard to extract silk from spiders, and each spider has only a small amount of it.

Spiders use their silk in a variety of ways, as we will see below, but Orb weavers are the spiders most of us are familiar with - the type that builds webs in trees and bushes and the corners of our ceilings. When the orb web has deteriorated and is no longer useful, many spider species will destroy it, eating up all the threads so it can recycle the raw silk material. Spiders may leave the heavy bridge thread so that they can easily rebuild the web at a later point.
3

Weaponry

While many spiders use their silk to trap their prey, protect their young or build their nests --- the Bolas spider uses it as a range weapon. These spiders do not spin the typical web. Instead, they hunt by using a sticky 'capture blob' of silk on the end of a line, known as a 'bolas'. First, they attract their prey (usually moths or moth flies) with potent pheromones designed specifically for luring their victims. Then, swinging the bolas around and letting it go, the spider may snag its prey rather like a fisherman snagging a fish on a hook.

The Net-Casting spider also uses its web for other than hanging. She will spin little nets that she will then hold with her front legs, suspended above the forest floor, waiting. When she sees her prey, she uses the net exactly as one would trap a cat with a pillowcase.
4

Fishing

The fisher or raft spider is able to walk across the surface of a pond or other body of water by skating like a water strider. When it detects prey (insects or tiny fish) under the surface, it can quickly dive to capture its dinner.

Diving water spiders breathe air just like other arthropods, but they live most of their lives underwater. The trick is the spider's diving bell which it builds from its silk. To build the diving bell, the spider first forms a web platform underwater, typically connected to a plant. Then it carries air bubbles down under the web, on the underside of its body. It releases the air bubbles under the web to gradually build a stable underwater air pocket -- the web keeps the air bubbles from rising to the surface. The spider ventures out to catch fish, tadpoles and other pond animals, and brings the prey back to the diving bell to eat it. It also mates, lays eggs and raises spiderlings in the bell.
5

Hydraulics

Jumping spiders, one of the more common types of spiders world-wide, have the ability to jump great distances -- as far as 50 times their own length. The thing that is the most amazing about these jumpers is that they don't have particularly strong muscles in their legs; they actually spring forward using hydraulic pressure. A powerful muscle in the cephalothorax squeezes fluids from the body into the legs to make them expand.

With more than 5,000 species around the world, jumping spiders are one of the more common spider varieties around. They're characterized by large eyes, which help them spot potential prey at a good distance. In contrast to web-spinning spiders, most jumping spiders hunt sort of like cats, stalking their prey and then springing on them at high speed.
6

Senses

While most spiders have multiple pairs of eyes, vision is a secondary sense in the vast majority of species (the notable exception is jumping spiders, which have excellent eyesight). Most spiders primarily interact with the world through tactile sensation. They are covered in highly sensitive hairs that pick up even low-level vibrations in whatever the spider is standing on (the ground, floor, leaf or web, for example). Many spiders have additional hairs, called trichobothria, which pick up vibrations in the air (sound). In some species of Tarantuala, they can even use their bristles for defense, shooting them off their bodies to embed in their enemies.
7

Societies

The majority of spider species are aggressive and solitary creatures, but there are about 40 species that have something in common with ants and bees. They are social.

Most species of social spiders live in the tropical regions of the world where insect size and density is highest but there are a few in the eastern US. By building a communal web, it is thought that the spiders think to increase their opportunities to catch prey. Having a larger web and multiple spiders to work together to subdue prey allows them to prey on larger organisms that would be impossible if they led a solitary existence. The colonies can grow large enough to take down birds and bats as well as very large insects.

What is also very interesting is that recent studies have shown that social spiders do not do as well as solitary spiders... that raising the young with multiple caretakers has resulted in a higher death rate. It is thought that the more agressive, solitary mothers do a better job of raising their own young than a large community of (hippie)spiders working together.
8

Trap Builders

There are a number of species of spider that do not spin webs, but instead roam the ground. The Wolf spiders and Tarantulas, notably. But there is a subset of wolf spider that builds tunnels, funnels and burrows in order to hide and trap their prey on the ground. These dudes tend to be very non-agressive but when threatened they raise up their front legs in an effort to appear larger and more intimidating to potential predators. That would be enough for me, certainly.

Trapdoor spiders are ground dwellers, with a burrow lined with silk of up to 10 inches in depth and around 1 inch in width - prefers nesting in drier exposed locations. It often has a wafer-like lid on the burrow entrance that they hide behind and spring open, dragging their prey inside when opportunity strikes.

Funnel Web Grass spiders are timid and non-aggressive as well. These spiders are often called grass spiders because they construct their webs in tall grass, heavy ground cover and the branches of thick shrubs. Rarely will a funnel web spider be seen indoors.

Wolf Spiders also create burrows from which they lurk, sometimes with a lid or covered by leaf litter or grass woven with silk as a little fence around the rim. They also rove the ground at night looking for prey, much like the wolf they are named after. It can move very rapidly when disturbed.
9

Bird Killers

Goliath bird-eaters are the world's largest species of tarantula, and considered the world's second largest spider (to the Huntsman - but they still rule in the weight class). Tarantula is a generic name for hairy spiders. This hairy spider has a leg span of 12 inches across, or about the size of a dinner plate or small pizza, and they can weigh 2.5 ounces. Although they are called Bird Eaters, they rarely eat birds... but they do feed on small animals and have been known to fight and kill poisonous snakes.
10

Regeneration

Arachnids, just like insects, have external skeletons (exoskeletons), which is their skin or shell. When a spider moults it splits open its old skeleton and wriggles out of it, the new skeleton that was growing underneath is soft and pliable, for a short while. The spider, once it is free stretches the new skeleton to allow some room for new growth, the new skeleton then hardens. And, like reptiles, spiders can regrow lost limbs when they regrow a new skeleton.

Spiders moult to grow larger, but when they have lost a limb, their moult takes a considerably longer amount of time to do... leaving them vulnerable for a longer period of time. Tarantulas, being ground dwellers, are the most vulnerable, as their new exoskeletons can sometimes take a few days to harden back to the point where their armor is a defense.

Showing items 1 - 5 of 10

Insect Control

Spider Silk

Weaponry

Fishing

Hydraulics

Senses

Societies

Trap Builders

Bird Killers

Regeneration