Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than 6 mm (1⁄4 in) in length, and herbivorous. About 97,000 species of weevils are known. They belong to several families, with most of them in the family Curculionidae (the true weevils). Some other beetles, although not closely related, bear the name "weevil", such as the biscuit weevil (Stegobium paniceum), which belongs to the family Ptinidae. Some weevils have the ability to fly, such as the rice weevil.