Bat
Microbats make use of magnetoreception, in that they have a high sensitivity to the Earth's magnetic field, as birds do. Microbats use a polarity-based compass, meaning that they differentiate north from south, unlike birds, which use the strength of the magnetic field to differentiate latitudes, which may be used in long-distance travel. The mechanism is unknown but may involve magnetite particles.
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.