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.
Magnet fishing
It is thought magnet fishing was initially started by boaters using magnets to recover fallen keys from the water. Today magnet retrieval tools are specially designed to retrieve items that are lost at the bottom of bodies of water. There are two main types of magnets used in the hobby: double sided and single sided.