This group gathers Arachnids subcategory members belonging to the order Araneae, the spiders, the largest and most diverse arachnid order, found on every continent except Antarctica. It spans web-building species such as the golden orb-weavers and the various widow spiders, whose potent venom and distinctive markings make them among the best-known dangerous spiders in the world, wandering hunters that build no web at all, such as the wolf spiders and the large, fast-running huntsman spiders, and the jumping spiders, a family remarkable for sharp, forward-facing vision and, in the genus Portia, a documented ability to plan multi-step hunting strategies against other spiders, unusual problem-solving behavior for an animal with such a small nervous system. It also includes the tarantulas, a family of large, often heavily built and hairy spiders many times the size of most other spiders, several kept in captivity despite a popular reputation for danger that considerably overstates the medical risk most species actually pose to a person. Every member produces silk from specialized abdominal glands, whether or not the species in question uses it to build a web.