Spiders are not including insects because all insects have 6 feet, while the spider is legged 8. Spiders do not experience metamorphosis. After the eggs hatch, small spiders come out and change the skin several times. Small spiders are similar in shape to adult spiders. Female spiders are usually much larger than male spiders. The male spider should approach the female with caution because it is dangerous. Sometimes male spiders do not marry, but are eaten by the female spider. It is also often the case that the female spider feeds on the male after the mating.
Spiders are present all over the world and occupy all ecological environments except in the air and open ocean. Most spiders are small (1.5-8 mm long), some of which are large enough like Tarantulas (75-85 mm body length). The male spider is always smaller than the female spider and has a shorter life cycle.
