I spy with my little eye......a bee in the wall!

On the way to our allotment and cemetery sites in Sonning, Berkshire, we noticed some very dark looking bees flying back and forth to a crevice in a stone wall. The crevice was bathed in early morning sunshine (what little we had last week!), and the bees (particularly the one in this picture) was happily digging, what looked like, a tunnel further into the wall. We believe the bees were Anthophora plumipes, which are known to build their nests in the ground or in the soft mortar of walls.