What recent discovery tells us how sharks find their prey by smell?
A shark's sense of smell is directional, much as our hearing is. Close your eyes and listen. You can tell the direction that a sound comes from because it reaches one ear slightly before the sound reaches the other. That lets our brain tell where the sound came from. A shark's nose does the same thing with scents in the water, detecting very slight differences in the concentration of scent molecules in the water. Researchers found that even with very tiny differences, the sharks would still turn towards the higher concentration.