New research reveals that mantis shrimps make use of a sun compass to find their way home. It seems to be based either on the sun's azimuth or on polarisation patterns in the sky (‘e-vectors’) - both of which are often visible beneath the surface, at least in shallow water.

When clouds conceal the sky, however, they fall back on DR or path integration.

They’re the first marine animals in which these abilities have been demonstrated, though many insects can do similar things.

Congratulations to the authors, Rickesh N. Patel and Thomas W. Cronin, of the University of Maryland.