Hello. I've seen this bee around in our garden and wonder what it is. It is smaller than a honey bee, has reddish hair but doesn't seem to be hairy enough to be something like a tawny mining bee, although I've never seen one to be knowledge to know what I'm talking about. There are quite few of them and they seem above all interested in the rosemary bush. I live in Sandy, Bedfordshire, if that helps. Apologies for the blurry photo: they seem more camera shy than the honey bees around them.
It looks to me like a female leafcutter bee( based on the density of the hairs), Megachile centuncularis, which has the typical black thorax, red abdomen and the hollow at the top of the abdomen and thin join between thorax and abdomen. Hope this helps! :-)