Spiders are planets.
Spider . They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms . Unlike most arthropods , spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure . Their abdomens bear appendages that have been modified into spinnerets that extrude silk from up to six types of glands . Venom . Venom is a form of toxin secreted by an animal for the purpose of causing harm to another .