The 400 living species of sharks defend themselves in a variety of ways that vary from species to species. Large species, such as great whites, basking sharks and whale sharks derive protection from their size; they are too big to represent potential prey for any species except humans. Other species, such as carpet sharks, rely on their flattened morphology and cryptic coloration to avoid the detection of predators.
In addition to attributes such as size and camouflage coloration, sharks rely on their powerful senses to avoid danger. Sharks can see reasonably well, but their best senses are smell, hearing and their lateral line sense, which allows them to detect the movements of other objects near them without looking. By using these senses, small shark species often detect predators from great distances. Sharks are capable of tracing blood through the water for a distance of more than a quarter-mile.
Sharks are also very intelligent creatures that make good decisions when dealing with predators. Although the primary driving force of shark intelligence has been the intelligence of some of their prey species, such as dolphins, their intelligence also helps them to protect themselves. When confronted by a threatening predator, sharks also engage in a number of exaggerated body postures, which often help to dissuade would-be predators.