Reply to Debbieb
Wasps will invade bee nests, including honeybee hives after brood prey and honey/pollen stores. The bees will defend themselves. I wonder if you have not rather seen something else. Your rust-coloured bees sound like mining bees, Andrena fulva or Osmia rufa. These 'solitary' bees make individual small tunnel nests in the soil, which they stock with nectar and pollen for their grubs. Although they work individually, each female making her own nest burrow, they often colonize an area of bare soil together to make 'bee villages'. The males of both species are much smaller and slimmer than the large, stout, furry females. Could you have been seeing first females, then males?