Sense
Magnetoception (or magnetoreception) is the ability to detect the direction one is facing based on the Earth's magnetic field. Directional awareness is most commonly observed in birds, which rely on their magnetic sense to navigate during migration. It has also been observed in insects such as bees. Cattle make use of magnetoception to align themselves in a north-south direction. Magnetotactic bacteria build miniature magnets inside themselves and use them to determine their orientation relative to the Earth's magnetic field.
Bioelectromagnetics
Some usually aquatic animals, such as sharks, have acute bioelectric sensors providing a sense known as electroreception, while migratory birds navigate in part by orienteering with respect to the Earth's magnetic field. In an extreme application of electromagnetism, the electric eel is able to generate a large electric field outside its body used for hunting and self-defense through a dedicated electric organ.