Bumble Bee Identification Resource
Bat Box Recommendations and Resources
In the April 2022 Canadian Bat Box Project Newsletter (link above), Karen Vanderwolf suggests that bats prefer bat boxes attached to buildings that are larger in size than the single-chambered designs. Bats are also more likely to be found in bat boxes in rural forested areas although they can still be found in rural agricultural areas, suburban areas, and urban areas. Vanderwolf also points out that bats seem to prefer older bat boxes and it may be a few years until a new bat box has bats take residence.
The link above has several bat box designs that you could use to make your own bat box.