Mostly 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 survival. Their 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. This list includes all the cool facts about spiders that you could ever hope to learn.
How many spiders are there in the world? It is estimated that there are up to one million spiders per acre of land on earth, and in the tropics, that number is thought to be closer to three million. Are there any good things about spiders? Yes! Below are some of the more interesting facts about spiders.
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.
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 see in the video, 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.
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 more 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.
Spiders in eight of the world’s 109 arachnid families can catch and consume small fish. Some of them can even subdue fish five times heavier than they are. At least 18 species can actually catch fish. Some can even swim, dive, and walk on the water's surface. These particular hunters anchor their hind legs to a stone or a plant, with their front legs resting on the surface of the water and then patiently wait to ambush their prey. Just like with their webs, the slightest movement in the water or under their legs can spur them into attack. Beyond water-side hunters, there are several amazing species of spider that can actually swim underwater. They can submerge themselves for 20 minutes to an hour, actually creating a "diving bell" of air that surrounds their book lungs.