Lampreys have no jaws. Instead, they have a circular mouth with rows of teeth at the end of their long, eel-like bodies. Their mouths can suction, while the teeth scrape, making them not unlike a vacuum cleaner hose fitted with a stiff brush. Some lampreys feed on other species (parasitize), attaching their mouths to the side of large fishes and scraping up blood or flesh. A hole carved in the side of the host fish, coupled with natural anticoagulants added by the lamprey to keep the blood flowing, the host often dies. The lamprey detaches after several days and finds a new host. Young lampreys are not like vacuum cleaners. They are little, blind larvae that spend years buried in bottom mud where they filter feed. When they change into an adult form, some species become parasitic, attaching to a fish, and others just spawn and die.