A reproducible model for magnetosensitivity: earthworms in transparent soil reduce their cumulative movement in extremely weak magnetic field

The magnetic sense remains one of the mysteries of sensory biology.
Despite fifty years of extensive research, science seems to be at a
standstill. One of the major factors contributing to this scientific
stasis is the lack of simple, reproducible model systems. Here we examine
magnetoreception in earthworms held in transparent soil. Using video
recordings, and machine learning-based analysis, we show that earthworms
move significantly less when held in a near-zero magnetic field. This
effect of near-zero magnetic field on earthworm activity was highly
reproducible and significant through all trials. Furthermore, under some
circumstances the earthworms showed significant group magnetic
directionality, however this result was not reproducible. By using
earthworms in transparent soil and manipulating the magnetic field we
created a robust protocol that facilitates examination of magnetoreception
in a simple organism. This may serve as a crucial springboard in the
ongoing quest to unravel this mysterious sense.