A team of researchers have embarked on a project to try to save the UK's declining population of bumble bees.
Three species of bumble bees are already extinct in the UK
The group from the University of Southampton is in the Hebrides for the study, where farming is more traditional and rare bees more common.
They are using DNA to detect how many nests are on the islands, and to determine exactly how big a bee population has to be to survive.
Bumble bees are believed to be in danger of dying out in parts of the UK.
Dr Dave Goulson, in charge of the study, said: "Survival of at least five rare species is threatened by the spread of intensive agriculture destroying wild flowers and hedgerows, which are the bees' natural habitat.
"Colonies do not seem able to survive in small areas such as nature reserves and many are dying out.
"Three species are already extinct in the UK."
The researchers also want to devise ways for farmers to encourage bumble bees to flourish on their land, such as by sowing wildflower strips and restoring hay-meadows.
Unlike honey bees, bumble bees construct a fresh nest every summer. The queen produces many sterile female workers, male drones and future queens but all except the newly-mated young queens die with the first frosts of autumn.
The project is funded by a £130,000 research grant from the Leverhulme Trust, with £50,000 coming from the C.B.Dennis Trust.