What do female carpenter bees do upon returning to their nests?

When female carpenter bees return to their nests, one of their primary activities is to leave behind frass, which is a mixture of wood shavings, feces, and debris. This frass is typically the result of their efforts in burrowing into wood to create tunnels for nesting. As they remove the waste from their nesting chambers, it helps maintain the cleanliness and integrity of their nesting sites.

Leaving frass behind indicates that the female carpenter bee is actively using and maintaining her nest, which serves both as a sign of her presence and as a potential marker for other bees. This behavior showcases the nesting habits of carpenter bees, highlighting how they manage and utilize their burrows as safe places for their offspring.