When you think of a spider, you probably picture a big, round web with its resident spider poised in the center, waiting for a hapless fly to land in the web's sticky strands. With few exceptions, you would be thinking of an orb weaver spider of the family Araneidae. The orb weavers are one of the three largest spider groups.
The family Araneidae is diverse; orb weavers vary in colors, sizes, and shapes. The webs of orb weavers consist of radial strands, like spokes of a wheel, and concentric circles. Most orb weavers build their webs vertically, attaching them to branches, stems, or manmade structures. Araneidae webs may be quite large, spanning several feet in width.
All members of the family Araneidae possess eight similar eyes, arranged in two rows of four eyes each. Despite this, they have rather poor eyesight and rely on vibrations within the web to alert them to meals. Orb weavers have four to six spinnerets, from which they produce strands of silk. Many orb weavers are brightly colored, and have hairy or spiny legs.