YOU may be spotting bodies of dead bumblebees lying across pavements near you in the summer months.There are several reasons for this, some to do with the weather and some very much due to humans.Bumblebees are social, living in colonies that are maintained by very active workers with a relatively short lifespan of four to six weeks. This means, that in a relatively short space of time, older bees die off and to prevent disease making its way through the colony, the healthy young workers bring out their dead, moving them far away from their colony.