Busy Bees

We've been thinking of building a bee house in our garden to encourage our disappearing honeybees, but nature has already beaten us to it. There seems to be a little colony of bees living in one of the airbricks near our front door. They are small stripy yellow bees - they are too speedy for me to get a photo, but I think they might be white tailed bumble bees . I am very happy for them to live there so long as they don't start coming in the house!