Mason Bees

Two years ago I purchased a mason bee hive and set up in the backyard without a single taker. Last year, I moved to the front and about 10 bees moved in and sealed themselves for the winter. Yesterday, I put the hive back up and the whole thing was buzzing today. I'm in love. There's a nice description of mason bees here. 

I'll need to try the wood block method and put one up in the back in a better spot. 

Here are the pics of the bees and the hive.