Solitary bees use door screw holes to build egg chambers

A homeowner discovered bees hovering around screw holes in a plastic front door, later finding the openings packed with a hard, gray, cement-like substance. After seeking information on Reddit, online commenters identified the material as mud used by solitary bees, such as mason bees, to construct protective egg chambers.

Unlike species that live in large hives, solitary bees utilize small existing cavities, gaps, and drilled openings to build nesting sites. These artificial voids in modern homes mimic natural sheltered spaces like dead wood or stems. As manicured yards and expanding built environments reduce natural habitats, wildlife often adapts by using available household hardware as makeshift nurseries for their young.