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.
Magnetoelectric effect
Historically, the first and most studied example of this effect is the linear magnetoelectric effect. Mathematically, while the electric susceptibility formula_1 and magnetic susceptibility formula_2 describe the electric and magnetic polarization responses to an electric, resp. a magnetic field, there is also the possibility of a magnetoelectric susceptibility formula_3 which describes a linear response of the electric polarization to a magnetic field, and vice versa:
The tensor formula_6 must be the same in both equations. Here, P is the electric polarization, M the magnetization, E and H the electric and magnetic fields. The SI Unit of α is [s/m] which can be converted to the practical unit [V/(cm Oe)] by [s/m]=1.1 x10 ε [V/(cm Oe)]. For the CGS unit, [unitless] = 3 x 10 [s/m]/(4 x π)