Many living beings can distinguish direction and position by using geomagnetic field, while biomagnetites can be found in these living beings, so scholars think that there are magnetoreceptions existing in these living beings which are formed by the biomagnetites and outer organic tissues (including the nerve). The magnetoreceptions interact with outer magnetic field and can transform the magnetic information into neural information, so these living beings can have response to it. The theories of biomagnetite magnetoreceptions include the model of single-domain magnetite magnetoreception and the model of superparamagnetic magnetite magnetoreception. In magnetotactic bacteria, there are many typical single-domain magnetites, so in this paper, the magnetic model and working mechanism of the single-domain magnetite magnetoreception are discussed qualitatively from the point of view of theory of magnetism taking the example of magnetotactic bacteria. In the outer magnetic field, each single-domain magnetite which is surround by biomembrane can be forced, and the single-domain magnetite transmits the force to the outer biomembrane and can be accepted by mechanical receptor in the biomembrane, then the force can be transformed into a stimulus signal which can cause the behavior of the bacteria; Another case may also exist, the single-domain magnetites combine with the biomembrane tightly, the force can open or close the ion passageway thereby influencing the inflow of ions and influencing the transmembrane potential, so stimulus signal can be produced; The signals can be magnified because many single-domain magnetites and biomembrane exist.
