Its been pretty cold here lately but we have had a few sunny days and for the last two or three I have been finding small clusters of dead or almost dead bees outside on the edge of the wooden platform my hives our one. Each group has about six to eight bees, with their heads together, not moving. If I get to them in time and scoop them up and warm them they revive and seem okay. Its like they are lost and cant find their hives but they find each other and try and cluster in the open for warmth.

Any ideas? I've never seen this before.