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Sunday 1 April 2018

Spider

The spider is a joint-legged animal of the class Arachnida. Unlike insects, the head and breast are merged to form the cephalothorax, connected to the abdomen by a characteristic narrow waist. 

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ANATOMY 
Most spiders have eight eyes. Spiders typically have a main set that can create images while the secondary sets can only detect light and shadow.

A spider has transparent blood.

Spiders are able to climb walls thanks to the hair-like setae on their bodies, which generate 3-4 times their body weight in surface force.

Spiders lack leg extending muscles. They extend them using a system of hydraulics powered by their blood pressure. When they die, spiders' legs curl up because the blood pressure is gone. 

BEHAVIOR 

Nearly all species of spiders are carnivorous, capturing and eating other insects.

Scientists have calculated that spiders may eat twice as much prey as humans, 400-800 tons a year.
The black widow can eat as many 20 mates in a single day.

Despite the crippling fear they arouse in millions of people, just a few of the 45,700 types of spider in the world are deadly to humans.

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Spiders can be affected by different drugs, like cannabis and LSD, which shows in their web-making. This phenomenon has been studied by NASA.

Spiders can sense electrical currents in the air and use them to launch themselves upward, traveling up to hundreds of miles. Occasionally a “mass ballooning” occurs, where so many spiders descend from the sky it looks like snow

Some spiders disguise themselves as ants by pretending their two front legs are antennae.

More than 300 species of spiders are known to mimic the outward appearance of ants, a phenomenon called myrmecomorphy. 

POPULATION 

An estimated 1 million spiders live in one acre of land. The number might be closer to 3 million in the tropics.

In 2009, four acres of spider web engulfed a building in Maryland. It was estimated over 107,000,000 spiders lived there.

It is estimated that a human is never more than 10 feet away from a spider.

A baby spider is called a spiderling.

Although most spiders live for at most two years, tarantulas and other mygalomorph spiders can live up to 25 years in captivity.

The world’s oldest known spider lived to be 43. Named Number 16, the trapdoor spider died after she was violently attacked by a wasp in Western Australia.

SPIDER WEB

The word "spider" is from the Old English word "spithra," which means "spinner." The word "spinster" is also related and means "one who spins thread."

The ancient Greeks used spider web clusters to stop bleeding in soldiers. They combined honey and vinegar to clean out the wounds. Then a wad of spider webs would be placed on top and held until the bleeding reduced.

On the run from King Edward I, Robert the Bruce found himself on the little island of Rathlin off the Irish coast. While hiding in a cave there, the depressed Scottish king watched a small spider spinning it's web. Six times the spider tried unsuccessfully to secure it properly but it kept going and finally the seventh time, it did it. This was a parable for Robert not to be discouraged by failure but to go out and liberate his country despite setbacks that were bound to occur time and time again.

Something common to all 40,000 species of spiders is that they all spin silk.

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An inch-thick rope of spider's silk can withstand up to 140,000 pounds of pressure.

Spiders, in part, store their memories and cognitive abilities in their webs. Destroying a web partially erases a spider's memory.

Spiders tune their webs like guitar strings, tightening and loosening strands so they can read the different frequencies caused by intruders and determine where/how big the intruders are, if they are predator or prey, or if they’re just a potential mate flirtatiously strumming their strings.

Spider silk transforms from liquid protein to solid thread when it leaves the body.

In 1973 two spiders named Arabella and Anita on Skylab became the first to spin webs in space.
Hummingbirds use spiders' webs to glue their nests together.

UNUSUAL SPIDERS 

Out of close to 46,000 discovered species of spider, only a single one has been found to be a herbivor. 

The central American spider species Bagheera kiplingi inhabit trees that produce protein-rich buds on their leaves.

The vampire spider is attracted to the smell of human feet.

At 22,000ft, the Himalayan jumping spider is the highest-living predator on the planet.

The Anelosimus eximius, a species of spider, forms armies 50,000 strong that work together to maintain their webs and capture prey.

The South American Goliath birdeater is the world's largest spider, according to Guinness World. Records with leg spans of 11 inches and bodies nearly 5 inches long. The spider can weigh more than 6 oz. (170 grams) — about as much as a young puppy

Goalith Birdeater By Sheri (Bellatrix on Flickr)

RELATIONSHIP WITH HUMANS 

Arachnophobia – a combination of the Greek words for spider and fear – is among the most common phobias in the world, affecting about seven per cent of the population.

When arachnophobia sufferers see a spider, they can become extremely upset, have trouble breathing, sweat excessively or even experience heart problems.

Women have been found to be more than twice as likely to be scared of spiders as men.

Famous arachnophobes are said to include Justin Timberlake and JK Rowling – who included giant man-eating spiders in her Harry Potter series.

A Peppa Pig episode was banned in Australia because it tells children that “spiders can’t hurt you”
Spiders don't feed on human blood, so they have no reason to venture near a slumbering human on purpose.

Despite Australia being known for deadly venomous variants of spiders such as the Funnelweb and Redback, nobody has died from a spider bite in the entire country since 1981. This is largely thanks to antivenoms.

FUN SPIDER FACTS 

 "Number 16," a wild trapdoor spider who lived in an Australian burrow, was the oldest known spider. She was studied by researchers from 1973 until 2016, when her burrow was found damaged and empty, likely due to a parasitic wasp attack. Number 16  was 43 years old.

A writer by the name of “Lisa Holst” created an article in 1993 that “around 8 spiders crawl into your mouth every year whilst you sleep”, but the whole thing was made up to prove that the internet was gullible and users don't fact check its sources. 


At least 95 per cent of the spiders in your house have never been outside.

A ladder to enable spiders to climb out of baths was patented in the UK in 1994.

Spiders can fly for miles and have been found 2.5 miles above the Earth's surface.

Sources Daily Mail, Pestworld

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