We have recently had squirrels showing up in the yard and decided to encourage them to stay. My son and I are building some dens for them. These are nothing special, built with big box pine. We cut the parts for 4 boxes. We donated the first to a local nature preserve. The other three are for the yard.
The dens we build are based on plans from the Missouri Department of Conservation. There are nice PDF plans for the dens on the page.
-- We must guard our enthusiasm as we would our life - James Krenov