http://www.pnas.org/content/early/2014/05/29/1408039111.full.pdf+html this surely explains why my bees get lost in the homogenous environment of the greenhouses up north. *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html