Harvestmen are not spiders – they inhabit their own order, the Opiliones. Like spiders, harvestmen have two major body sections and eight legs. Unlike spiders, the two body sections of harvestmen are broadly joined and no web spinning organs are present.
Harvestmen will feed on many soft bodied arthropods, including aphids, caterpillars, leafhoppers, beetle larvae, mites, and small slugs.
Of the many species of harvestmen known, Phalangium opilio tends to be the most common. Adult body length is approximately 3.5–9 mm, with males generally smaller than females.