Most spiders weave webs to catch their prey and to rest in. Although some use blades of grass or man-made objects, such as stop signs and fences, as anchors for their construction, many have evolved to use trees. In fact, several spiders live primarily in the trees, catching winged insects or whatever has the inclination to climb.
Delena, or huntsman spiders, are a genus of spiders with several distinct species. The huntsman species Delena cancerides is light-to-medium brown in color and lives under loose bark of trees, where the spiders harbor their young. Male huntsman spiders grow up to 24 mm long; females grow up to 28 mm long. The toxicity of a huntsman's bite is unconfirmed, but it may cause mild irritation and illness. Aside from living trees, huntsman spiders may enter houses in search of a new home.
Growing only as large as 7 mm, the Hedana species spiders often go unnoticed, living on the dark bark and branches of the eucalyptus tree. These spiders vary in color from dark brown to light green and use their color to blend in with the tree, avoiding predators.
Evolved to appear as a nodule or loose portion of bark, several Dolophones species spiders wrap around small twigs and attach themselves to bark. These spiders grow up to 9 mm long, with males only reaching 6 mm. They are distinguished by a large, dish-like upper abdomen that helps complete their camouflage. These spiders rest on the bark during the day and hunt at night, with a bite that incapacitates small insects but is small enough to be harmless to humans under most circumstances.
With some species going completely without eyes, the spiders in the Dictynidae family, or branch tip spiders, are in need of good camouflage to escape predators. Branch tip spiders weave mesh webs underneath leaves and on the tips of branches, where they wait for small flying and crawling insects. These spiders range in size from 1.3 to 8 mm long.
The crab spider, or Stephanopis corticalis, is a tree-dwelling spider that, like other tree dwellers, uses the color of the bark as camouflage. These night feeders grow from 4 to 12 mm long and move slowly over the tree bark in eucalyptus forests. Whether these spiders are dangerous to humans is unknown.