The calls are generally unmusical and are described as guttural, harsh and rasping. Other calls include rasping croaks, when alarmed, and hisses. Limpets scrape algae from rocks using radula equipped with exceptionally hard rasping teeth. They have six signals&colon; squeaking or whistling, rasping, barking, whining, screaming, and nonvocal sounds. Attachments are available for sawing, sanding, rasping, grinding, scraping, cutting, and polishing. Mouthpart morphology in the genus ranges from sponging mouthparts to mouths with rasping teeth. Grazers use scraping, rasping, and shredding adaptations to feed on periphytic algae and macrophytes. Grazing invertebrates utilize scraping, rasping, and browsing adaptations to feed on periphyton and detritus. Snails eat solid food by rasping it away with their radula. The call is a rasping whistle or rattle. The pure clarity of a youthful voice, leading into a more bluesy, rasping, mature sound. Secondly (apart from bivalves) it has a rasping tongue called a radula used for feeding. Others feed on macroscopic 'plants' such as kelp, rasping the plant surface with its radula. It makes loud, high-pitched and short rasping sounds, especially when seeking a mate. The mouthparts are designed for rasping and "E. esculentus" feeds on algae and encrusting invertebrates.