Mason Bee houses

Mason bees are native to North America and once you put out a nesting box they should start using it within a few weeks. There is some maintenance that needs to be done periodically though. The tunnels need to be cleaned out to prevent and minimize disease and parasite issues. The following information from the Xerces Society should provide the information you need,
https://www.xerces.org/wp-content/uploads/2009/11/tunnel-nest-management-xerces-society.pdf
Deb