From BBC News:
Bumblebees can navigate their way home over distances of up to 13km (eight miles), a UK research team has shown. The study also found only worker bees seemed to have this homing ability. Bees pollinate flowering plants and therefore play a crucial role in food webs, but numbers of the insect in Britain have been declining recently. The team said the homing research would inform conservation strategies that sought to adapt landscapes to create optimum habitats for bees.
The University of Newcastle-led group took some 20,000 bumblebees belonging to the common species Bombus terrestris and tagged them with tiny identification numbers. The bees were then dropped in different places around north-east England and left to make their way back to the nest. The scientists set up a webcam in the hive to record the homecomers. Early results show the bees will fly varying distances but some that were left at a garden centre in Heddon on the Wall in the Tyne Valley – about 13km from their nest – could get home safely. This is a big leap on from previous studies which had suggested bumblebees could forage out to about 5km (three miles) from the hive.