I am thinking of making a Mason Bee box. Not so much to attract mason bees although I think that would be cool too but I have seen many leaf cutter bee nests. I thought they were mason bees but now I see there is a difference. They apparently use the same kind of box. While they damage leaves the custom made boxes actually cut down on the damage from the bees because they don’t need to cut as many leaves to make their nest. Also they won’t attack your vehicle or other machinery if they have a proper house. In addition they will pollinate your plants and hopefully produce more fruit. I have only seen two honey bees since the season started and I suspect that is why my squash is suffering. It’s too late in the season I think for the leaf cutter and mason bees but I would like to get ready for next year. Here is a link that talks about all about them.
Here is another good link