The mason bee is a gardeners best friend. This little bee does not live in a hive nor does it make honey but it is an amazing pollinator. A single female mason bee will visit nearly 2,000 blossoms a day. Unlike honey bees they will start earlier in the morning, finish flying later in the day and dull weather doesn't prevent them working. The mason bee does not sting which lends itself well to sharing time in the garden with them. They do not look like the traditional honey bee, mason bees are usually black to blue in color and resemble a house fly. Mason bees make their homes in small holes usually left by burrowing insects, however you can mimic this natural occurrence by building a mason bee house with several holes a piece of wood.
West Coast Seeds or Wildbirds Unlimited (which is where I got my bees and cardboard tubes from).