Premise: Spiders ( order Araneae ) are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom . They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms . In all except the most primitive group , the Mesothelae , spiders have the most centralized nervous systems of all arthropods , as all their ganglia are fused into one mass in the cephalothorax . Unlike most arthropods , spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure . Social behavior ranges from precarious toleration , as in the widow spiders , to co-operative hunting and food-sharing .
Hypothesis: Spiders are planets.
Label: CONTRADICTION