Why do spiders have 8 legs? why cant they just have 2 or 4?

Question

what makes spiders so special to have so many legs?

Answer 1

Spider, common name for about 34,000 species of arthropod animals having eight walking legs, anterior appendages bearing fangs and poison glands, and specialized reproductive organs on the second appendages of the male. They commonly make extensive use of silk that they spin. Like other arachnid species, spiders are terrestrial, although a few have adapted to freshwater life by trapping air bubbles underwater and carrying the bubbles with them. Spiders are numerous and occur worldwide. Although most are less than 1 cm (less than 0.4 in) long, the largest has a body length of about 9 cm (about 3.6 in), and spider leg spans can be much greater.

Structure
The body structure of a spider is similar to that of other arachnids in being divided into an anterior cephalothorax, or prosoma, and a posterior abdomen, or opisthosoma. The two parts are separated by a narrow stalk, or pedicel, which gives the animal a flexibility that facilitates its use of silk. The cephalothorax ordinarily bears four pairs of simple eyes that tend to be larger in hunting spiders and smaller in spinners of elaborate webs. Each of the first pair of appendages, or chelicerae, bears a fang with an opening from a poison gland at the tip. The next two appendages are pedipalps, rather leglike but generally modified into a kind of feeler. In the male the pedipalp bears a peculiar copulatory apparatus called a palpal organ. Also on the cephalothorax are four pairs of walking legs. On the abdomen are located modified appendages, the spinnerets, used in secreting silk. Respiratory openings on the abdomen lead to the so-called book lungs (named for their layered structure) or a system of tubes (tracheae) for carrying air, or both.

Answer 2

You try spinning a beautiful, strong, symmetrical web in one hour with just 2 legs. Or scaling up walls and catching a cockroach that is as big as you are and much heavier and struggling to get away. Or jumping from ambush position to catch a quick moving fly and succeeding.
They use what they have very well. Eyes too - how many pairs do spiders have again? Wonderful creatures!　
Wow! Devon 1754! Great info! Yes, 8 eyes too! And you forgot to mention that in times of famine, when they can't catch food, they can live off their own silk! How amazing is that! Some of the huge ones, that don't spin webs, will eat cat food or dog food if it is available. 　

Answer 3

They really have 8 legs, go to this site for more info on spiders.

Answer 4

They are arachnids a species that includes crabs and lobsters. Nobody knows why this particular species evolved 8 limbs but it must have happened when the early ancestors lived in an environment where 8 limbs was an advantage so they thrived..

Answer 5

because they live in places off the ground and build webs which looks very hard, just to catch their food,so the extra legs help them to climb,have a better grip and balance, but spiders aren't evil. they're clean creatures that help WAY more than you think at keeping insects away, like wasp or even killer bees

Answer 6

They can have 4 legs, or even 2, if you pull the others off.

Answer 7

Because they are greedy. Seriously though, it seems that they have eight legs because this amount makes it easier to move around in different directions like backwards, sideways, up and down as well as forwards.

Answer 8

great answer devon1754 very interesting BUT I am still terrified of them and if there is one in the house and I am on my own then the spider can have the house because I am out of here.

Answer 9

suppose they're just like that to make them faster to catch flies and run over to trap them, scarier and also cos they need to run fast to avoid being squished by us. Might also help with spinning webs.also they come off easy so need some just in case

Answer 10

I think they use them when making their webs... still though it makes them 10 times creepier with 8 legs