Harvestmen are eight-legged invertebrate animals belonging to the order Opiliones (formerly Phalangida).
These arachnids are known for their exceptionally long walking legs, compared to body size, although there are also short-legged species. The difference between harvestmen and spiders is that in harvestmen the two main body sections (the abdomen with ten segments and cephalothorax, or prosoma and opisthosoma) are broadly joined, so that they appear to be one oval structure; they also have no venom or silk glands. They have a single pair of eyes in the middle of their heads, oriented sideways.