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Shark Attack!

closeup of shark's electrical sensors Hold your hands out about three feet apart. That's about the distance at which some large sharks can sense electric fields given off by prey. Move your hands so that they are about six inches apart. Smaller sharks detect electric fields at that distance.

All living things (even you) produce an electric field, given off by each heartbeat and muscle movement. A shark has special receptors located around the head that detect electric fields. These receptors can help a shark find a fish hidden under the sand by detecting its heartbeat. A shark also uses this sense to position its head and mouth when moving in for the final attack. This is the only sense a shark has that you don't share.

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