A Simple Mason Bee Nesting Unit

I just made a really simple Mason Bee nesting unit.

You can make these with 2x4 or 2x6 planks of wood. I used a 2x4 for this prototype because it is easier to manipulate. I cut the 2x4 into various lengths using my band say. You can easily use a good hand saw. It is just as easy.

I cut a 1x2 plank to equivalent sizes.

I measured and marked for holes 1 inch apart, and used a punch to start the holes. 

Using a 7/16 in wood bit, I drilled holes with a hand held drill. If you have a drill press available, It is a lot easier to get nice parallel holes.

I used a circular file to clean out the holes.

I cut a variety of block sizes.

I cut 5 by 5 inch pieces of parchment paper. You can get it in your supermarket. I rolled in around a standard pencil. The resulting tube is 5/16 in in interior diameter.

I inserted the paper tubes into the holes in the 2x4s. 

The paper tubes will be secured with the 1x2 pieces using wood screws.

Now, I will continue to roll and insert the paper tubes into my 2x4 pieces.

There are myriad ways to use these units. How would you make and utilize these units?