They do not use echolocation or sonar to navigate. No vocal chords are present, but vocalizations can be made for communication. No one knows how the sounds are made. Taste buds are present on the tongue and are used in selective feeding and recognition of others by tasting scent marks left by other individuals. A unique feature in Manatees is a constant horizontal replacement of their molars from the back of the mouth to the front of the mouth.
New teeth grow in at the back of the mouth as old ones disintegrate in the front of the jaw.
This progressive forward movement of the teeth moves about 1 mm per month. This is an adaptation to the protective mechanism of silicate formation in plants that would eventually grind the teeth to nothing. Little is known about social habits, but radio-tracking has show that manatees are essentially solitary but occasionally form groups of a dozen or more. The aggregation may coincide with mating. The dugong is distinguished from the manatees by its tail which has a straight or slightly concave tail.