Mason Bee Box
Mason bees are solitary bees that can pollinate plants 60 times more efficiently than honey bees, and require only about an hour a year to maintain. They are your native bees and are therefore hardier than honey bees. You won't get honey, but you will be guaranteed pollination.
The blue and yellow paint gives the bees reference points to identify their chosen holes.
The screen is to keep birds out.
The sheet metal is copper, and will never rust.
The box is made of Cambria, the trade name of wood that has been heat treated to be weather resistant. This box will never wear out and is easy to pull apart and reassemble. There are 4 screws on each side, remove them and the bee box comes apart. The 4 pieces of wood can be easily separated to remove the larvae. These are then kept in a container till spring when they will be placed on the top shelf of the box to hatch. Each piece of wood is numbered with 1 to 4 dots of yellow paint to align them when re-assembling the box.
The last picture is my bee box and shows the nests that have been filled and closed with either straw or mud. Some bees use leaf pieces to seal the nest.
The reference book called Mason Bee Revolution is available on Amazon.com. Highly recommended.