Avon,
United Kingdom 
Hi. I noticed last year some little yellow flies (about the size of a small housefly) flying low over my garden but didn't take too much notice of them. This year however there are a lot of little holes in the ground and these little flies are using them. Do you know what they could be. Gill from Bristol
15 Apr, 2015
Answers
Hi Gill any chance of a photo and are they biting at all?
15 Apr, 2015
Most likely bees, although actually, most ground bees aren't noticeably yellow, more brown/orange/red - most bees are solitary, and many live in small holes in the ground, usually in places where the soil is loose and free draining. They seem also to like very old paved areas, where the paving now has no mortar at all and the paving is well past its best. The masonry bee lives in soft mortar in older houses. As to precisely which variety of bee, need a pic to id really
15 Apr, 2015