Manatees are giant creatures but known to be gentle mammals. They are also called as sea cows and they don't harm humans.
They are herbivores and their diet consists of freshwater vegetation and sea grasses.
But this specific girl who was swimming freaks out when she saw a manatee coming her way. She immediately panicked as soon as she sees it.
She thought that it will harm and attack her and so, she screamed loudly asking her friends to help her.
However, her friends kept on teasing her because they know that the manatee was harmless creature.