A female and a male (in burrow) mantis shrimp (Odontodactylus havanensis) display to each other with polarisation reflections from antennal scales and uropod region of tail. The flashing regions indicate areas of polarisation shown through a polarised switchplate filter that alternates vertical and horizontal filter conditions at alternate video frames. As a result any area in the scene that polarised is seen flickering. The male appears either to court or to drive away the female; however, the information content of the signals in either direction is unknown. (Video by Alex Cheroske).