Hi All An illustration that stuck in my mind... I once replaced the roofs (outer covers) of a whole apiary, with ones that had brand spanking new 'Spangled galv' metal covers. It was quite comical to see the bees flip upside down as they flew over them. most crashed, but some made it to the other side and flipped normal again. I put this down to reversal of the polarisation of the light, caused by the reflection from the shiny surface... would snow also do this polarisation reversal? Best Regards & 73s... Dave Cushman, G8MZY Beekeeping & Bee Breeding Website... http://website.lineone.net/~dave.cushman