Many fish have an electroception sense, believed to be associated with the lateral line system. Sharks apparently have an electroception sense; a problem with the early submarine telegraph cables was the damage by sharks that sensed the electrical pulses.
The electric eel, besides its ability to generate high voltage electric shocks, actually uses lower voltage pulses for navigation and sensing prey in the turbid waters in which it lives.
The platypus is the only known mammal that has an electroception sense.