The Ultimate Spider Quiz

Of the 35,000 known species of spider, just under 10 percent -- about 3,000 -- are indigenous to the United States.

Scorpions and spiders are both arachnids, as evidenced by the fact that both they both have eight legs.

There are species of spiders whose body length is only 1/50 inch (0.05 cm).

The dreaded tarantula, with a leg span of more than 10 inches (25 cm), is the world's largest species of spider. While their bite is extremely painful, they are not capable of inflicting fatal damage to a human.

The fundamental difference between the body of an insect and that of a spider is that insects have three sections, while spiders have two. This is because whereas insects have a separate head and thorax, those of a spider are fused in what is known as a cepholothorax.

Connecting the two sections of a spider's body is a small tapered area known as the pedicle.

Spiders have two types of respiratory systems, trachea and book lungs, both of which are found in their abdomen.

After courtship and mating, female spiders retire to their lair, where they might lay as many as 3,000 eggs.

Spiders are carnivores; depending on the species, they eat other spiders, insects, small birds, and small lizards.

For its mass, spider silk is perhaps the strongest material known to man, yet it is very light. A strand surrounding the world would only weigh six ounces (170 grams).

Spiders are not immune to the sticky substance on their webs, and are susceptible to getting caught in them. They avoid getting caught by remembering the location of the sticky areas and deftly avoiding them.

The jumping spider is one of the few species with good vision. It stalks its prey, and then jumps, sometimes 40 times its own body length.

The trap-door spider, which can be found in the south of the United States, builds nests into the ground. It then covers the opening with leaves, creating a trap-door.

The crab spider resembles a crab because it walks sideways, and because two of its sets of legs are shorter than the others.

Like most spiders, black widows have poor vision, and cannot recognize the difference between their mate and other food.

The exoskeleton of a spider is made of cuticle, which is too hard to grow. Molting allows spiders to increase their overall size, shedding their old exoskeleton as they go.

Female adult spiders molt once a year, unlike adult males, who do not usually molt.

Tarantulas tend to avoid water, but are able to float and swim in it. They are also totally waterproof. They float and paddle to a safe spot, and crawl out of the water perfectly dry.

The blood of a tarantula does not clot, which means they will not stop bleeding once they start. They are essentially the spider equivalent of a hemophiliac.

Tarantulas are not only the world's largest spiders, they also live the longest; the females sometimes live more than 20 years.