Recent experimental studies have suggested that certain species can sense earth magnetic fields for navigation. However the exact magneto-reception mechanism is not known. Insight into this mechanisms and biomagnetism, magnetic fields that originate in biological systems, not only allow us to understand better different ways of visualizing the world but may also find applications in man-made sensors inspired by their biological counterparts. Here we describe a series of precision measurements of magnetic fields generated by dead and alive American

cockroaches (periplaneta americana) and obtain some clear conclusions.

Bio-magnetism with Atomic Magnetometer