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. It is the only truly vegetarian sea-dwelling mammals, manatees are at best only venture into the sea.
Dugongs eat vascular sea grasses that are comparable to terrestrial grasses.
The roots of the grasses are the most nutritious and prized forage item. Dugongs chew vegetation mainly with rough horny pads which cover the upper and lower palates. Adults only have a few peg-like molars on the back of their jaw. Juveniles also have premolars, but these are lost in the first few years. Adult male dugongs have short stubby tusks that evolve from incisor teeth.