There are more than 37,000 species of spiders of different shapes and sizes in the world. The largest spiders live in the rain forests of South America and are known by the people who live there as "bird-eating spiders." These spiders can grow up to 28 centimeters long and, as their name shows, they have been known to eat small birds. On the other hand, the smallest species of spider in the world lives in Western Samoa.
these spiders are less than half a millimeter long and live in plants that grow on mountain rocks. Some people like to keep spiders as pets. Tarantulas, for example, are very popular. They live in North America and can live for almost twenty-five years. Most people, though, don't like to touch spiders, and a large number of people are afraid of them because they think they are poisonous. However,in fact, only thirty of the 37,000 species of spiders are very dangerous to humans.
Spiders actually provide benefits to us by catching and eating insects such as flies and mosquitoes. Spiders are very different from other animals because they make webs to catch the small insects they eat. The silk of a spider's web is produced by special organs found in the lower part of the body. It is light, elastic, and strong; it is five times stronger than steel. The web will break up and finally return to nature as time passes, so it would be perfect for making such things as nets.
Some people have tried to keep spiders in order to make money. These businesses have never succeeded, however, because it takes 670,000 spiders to produce only half a kilogram of silk, and all of these spiders need living insects for their food. In addition, spiders are usually solitary animals and need to be kept alone.
「補食」は変換間違いで、正しくは「捕食」です。失礼しました。