harvestman, arachnid, often called daddy longlegs because of its eight long, slender legs. The harvestman has a rounded or oval body possessing glands that give off an acrid scent. Its food consists of a variety of organic materials, including fluids from fruits and vegetation, animal tissue, and even other harvestmen. The unrelated crane fly is also called daddy longlegs because of its long legs. Harvestmen are classified in the phylum Arthropoda, class Arachnida, order Opiliones.