Manatees and dugongs are not possessive about territory like other animals (such as dogs). They are not aggressive in any way and do not fight with each other. They are extremely gentle animals. Because they have no natural enemies, manatees and dugongs do net need to travel in large herds which offer protection to the members of the group. Individual manatees and dugongs form loose groups without regard to gender (male or female) or age. Their groups do not have a leader or a defined structure. Manatees and dugongs engage in social activities such as chasing, bumping, and sometimes body surfing together. They grab each other's flippers, put their mouths together, and nibble and kiss gently to greet each other. Manatees and dugongs are normally silent but can make high-pitched squeals to communicate fear, anger, playfulness, and maintain contact when feeding and traveling.