Some people think that humans are not good food for great white sharks, because the human body has a lot more bone and less muscle and fat than the shark likes. Some scientists think sharks attack humans because they have mistaken the human for a seal or sea lion. Seals and sea lions have blubber, which the shark likes. Other scientists think sharks' senses are good enough to tell that the human is not a seal. They think sharks do not know what the human is and bite it to learn more.