Good question. It seems really strange to us because we can’t do it but actually all vertebrates, including our ancestors once had this amazing ‘superpower’. Our lineage has lost this ability (probably because it is not very effective unless used under water) but sharks have kept it. Electroreception works a lot like other senses we are familiar with like hearing, smell or sight. There are special organs called Ampullae of Lorenzini concentrated around the front end of the shark, especially it’s snout or ‘rostrum’ which are filled with special sensory cells. These sensory cells activate when there is a change in the electric field around them sending signals via nerves to the brain. This is a lot like how sound waves are detected by specialised sensory cells in our inner ear, or chemicals are detected by specialised sensory cells in our taste buds. In all of these cases signals are then sent via nerves to the brain. To a shark it probably doesn’t seem any more strange than hearing or smelling. Wouldn’t it be amazing if humans could figure out how to do this again?