Solitary bee house.

My dad and I made this several years ago.

Solitary bee house in the prairie.

It was probably in '06 or '07.  I don't have the original plans, but I believe it was from a DNR publication.  If I can get the plans again, I'll post them.

Basically, it is a formation of three 2 x 6 boards, cut square at the bottom and angled at the top (to accommodate the roof).  The roof was made of, I believe, 1 x 8 boards.  I then tacked some spare shingles to the top.

We placed it in the middle of our prairie restoration project in the summer of '08.  As far as I could tell, it remained empty during the first year or two.  However, it slowly appeared to fill up with clay-capped cells.  I assume that these are solitary bee cells, but I don't know for certain.

Same solitary bee house years later, now in use.

Close-up of cells.  Beneath the grass are clay/mud caps of, likely, solitary bee cells.