Birds have a magnetic sense.
Fish have an electric sense.
What you are alluding to is called a TRANSDUCER, and the MEG shows the brain can act as its own transducer.
Without going into the details, our brains take imprecise and somewhat random computational elements (neurons) and put them in populations where they become at least 7 orders of magnitude more precise in the population.
The classic example is phase coding in the auditory system of the owl. There, the neurons have refractory periods in the low milli-seconds but the population resolves to better than a microsecond.