The harvestmen or daddy longlegs, an order of the class Arachnida; sometimes known as Phalangida. About 4500 species are known. They are common in temperate and tropical climates. Most are red, brown, or black and 5–20 mm (0.2–0.8 in.) long, although a few are only 1–2 mm (0.04–0.08 in.). Some large tropical species have bright iridescent colors and elaborate spines.