Spiders:

Fascinating or frightening?

Who is not afraid of creepy crawlies, especially those big, black, hairy-legged ones? There are millions and millions of varieties of insects and arachnida that inhabit our Planet Earth, but we have heard of or seen only just a few of them.

And, many of the creatures we encounter from the world of creepy crawlies are not very pleasant or friendly

creatures. Today, let's look at some of these creatures who are fascinating, though not as beautiful as the butterflies most of us admire so much, or deadly as the mosquitoes that have become public enemy number one these days with the dangerous diseases they are spreading among people.

One of the creatures we would like to focus on briefly today is the spider we are so familiar with, as all of us have seen them around in our homes sometime or another.

Like most insects, spiders too come in a wide variety of species; some are scrawny and spindly-legged, some are thick-set and hairy, yet others are huge, black and ugly or small and harmless-looking in appearance, though looks may be totally deceptive. There are many spiders that are very poisonous and harmful to man...

Presently over 30,000 species of spiders have been discovered around the world though many more may be crawling about, waiting to be discovered!

Spiders can live virtually anywhere in the world and most of them are poisonous, but only a few of them have fangs that are strong enough, and venom that is powerful enough to harm humans. That's why we are so lucky to stay unharmed with the many spiders crawling all over the planet.

One of the most feared spiders is the Black Widow Spider which is a small, round spider that loves to hide in quiet places. Found in many warm parts of the world, including USA and Europe, the Black Widow Spider is generally not aggressive but if attacked, it could bite you. The bite of a Black Widow Spider is not only terribly painful, but it could also lead to dizziness and even paralysis.

It is rarely fatal though, and today cures are readily available for such bites. Another poisonous spider is the Australian Sydney Funnel-web Spider, which is rather a large species. It is said that a bite from this spider can cause breathing problems and even heart failure. Of course, like for many other animal bites, medicine is now available to treat victims of these poisonous creatures too.

Two other spider species whose bites can be fatal, if neglected, are the Recluse Spiders of USA and the Brazilian Wandering Spider.

Have you heard of a variety of spiders called the 'Bird-eating spiders?' Well, even though they are so named, they actually do not eat birds, but some of this species, especially the larger ones, are known to eat small frogs, lizards and even snakes! Ranked among the heaviest and widest species of spiders, with weights up to 80g (3 oz) and leg spans up to 26 cm (10 in), these spiders are generally found in South America.

You must have noticed that some spiders are black in colour while some are light brown. Even though most of the spiders we come across over here belong to these two groups of colour, spiders come in different colours. There are some species of spiders that can change colour too like a chameleon. A crab spider such as the Misumena that is found in flowers can change colour to match the flower it is on.

It will stay on a flower lying in wait for a prey, changing colour over a few days, until it gets its prey.

Most spiders stay the same colour throughout their lives, but as they perfectly blend with their

 surroundings, they do not need to change their colour as camouflage.

We are so used to seeing spider webs in our houses that we believe that all spiders spin nice round webs. Well, you may be surprised to learn that not all spiders spin webs even though all spiders can make silk.

Like the different kinds of spiders, the webs too are different. Some spider webs are nice and round while some are woven in the shape of a hammock. Some spider webs are flat as sheets while some are simply trip wires radiating from the lair to trap insects that pass by.Have you ever watched a spider spin a web? It could be interesting to do so.

The next time you come across a spider spinning a web, take time to observe it doing so before you decide to destroy it. As we explained earlier, spider webs can be of different shapes. Similarly, the webs can be of different sizes too.

Did you know that a species of spiders known as the Tropical orb web spiders can spin webs over 5 m (16 ft) across? These spiders can produce up to 700 m (2,300 ft) length of silk strand from the silk gland in their body. The silk produced is said to be strong enough to actually hold a human!

The silk made from the gland in a spider's abdomen can be sticky, elastic or very strong. Some spider silk can be much stronger than steel of the same thickness.

It may be hard for you to think so because the spider silk threads we come across just break at the slightest touch, but it is true. This is why spiders can be fascinating creatures though they are so frightening at least in appearance.

There is so much about them that we do not really know and that is why we should take time to get to know these creepy crawlies better. A journey into the world of spiders can be so mind-boggling because what some species are capable of is beyond our imagination.

Fact File

* Spiders are invertebrate animals in the order of arneae within the larger class of arachnids.

* Study of spiders is known as arachnology.

* Most spiders do not really look after their young. They lay their eggs in a cocoon for protection.

Mother Wolf Spiders carry the cocoon of eggs attached to their spinnerets (the organ that makes silk).

* Spiders do not have wings, but many species can parachute or sail through the air by letting out a long thread of silk until they are carried away by the wind. Many young spiders leave their nest by using this 'ballooning' technique. In fact, they can be carried thousands of metres above the ground by this method.

* Male spiders are often smaller than the females. As most female spiders eat their mates, the males of certain species stoop to various tricks to save themselves from becoming a 'meal'.

There are many American Wolf Spiders that 'sing' to their female spider mate in order to distract her from eating them up. Another European spider species goes to the extent of presenting a gift of a fly wrapped in silk to the female as a meal so that she won't be hungry enough to gobble him up.

A species known as the Trapdoor spiders use the element of surprise. They lie in wait in burrows in the ground which are covered by flaps. As soon as a small insect passes by, the flaps open and the spider rushes out to grab the victim. The Spitting spider catches its prey by spitting sticky threads at its victims, especially flies. Some spiders use the sticky thread they can produce as lasses to catch prey.

* Spiders can detect vibrations travelling through the air from sources far away thanks to the specialised, vibration-sensitive hairs called trichobothria on certain segments of their limbs. These hairs have the ability to move in any direction and tell the spider the direction from which an object is approaching and even its size!