How many nesting holes do I need?
An easy rule to follow is to offer a nesting hole for each bee cocoon because each female bee is able to fill more than one nesting hole before her work is done. You may need to supply more nesting holes if the conditions are great for the bees.
While your bees are nesting, if you see the nesting holes are about 40% filled it means that the bees are nesting in the remaining nesting holes. When all nesting holes are filled or occupied by a bee, the female bees looking for a new nesting hole will fly away. It’s better to add more nesting holes sooner rather than later.