The Reimagining Bee Hotels project is an interdisciplinary collaboration between College of Design and the College of Agriculture and Life Sciences that develops and tests modular earthen bee hotels to support ground-nesting wild pollinators.

Project Overview

Team: College of Design, College of Agriculture and Life Sciences, Campus As A Classroom

Duration: Fall 2024 – Present

Status: In Progress

Focus: Life on Land

Primary Contact: Shawn Protz

Summary

While traditional bee hotels provide nesting space for solitary bees like mason and leaf-cutter bees, they fail to support the vast majority of native wild bee species, particularly in North Carolina where roughly 76% of native bee species nest in the ground rather than in hollow stems. Wooden bee hotels also face design challenges, including parasites, mold, and humidity. Funded in part by the NC State Sustainability Fund, this project bridges ecology and architecture to create better  infrastructure for bees. The project includes design and production of modular earthen bee hotels by School of Architecture students and faculty. The stacking block system is within a galvanized steel frame with cavity-nesting bamboo inserts in between 3D-printed ceramic blocks and earthen cob blocks. Five new hotels are installed at campus sites including Plant Sciences Building, Rocky Branch Refuge, Centennial Campus disc golf course, and D. H. Hill Jr. Library.

Current guidelines recommend placing overwintered bee cocoons in enclosed wooden emergence boxes to prevent pathogen buildup. However, research on safety and effectiveness is lacking. The team is also constructing and testing emergence boxes across different microenvironments (varying shade, sun, and vegetation cover) using untreated cedar and cypress. Environmental sensors track humidity and temperature, while non-invasive X-ray imaging and manual inspections measure bee emergence success rates. A student through the Campus As A Classroom program coordinates maintenance and collects field data on the emergence boxes.

Findings

Preliminary research and early field testing show that ground-nesting bees will readily utilize the earthen construction, providing proof-of-concept for the project’s new designs. Material testing in the Digital Clay Lab revealed key insights into block fabrication using North Carolina’s native, clay-rich Piedmont soil:

• Mixes with high sand content crumble easily. Incorporating a small fraction of binder with chopped straw cured without requiring kiln firing.
• Earthen blocks offer long-term resistance to weathering, but they may become too hard for bees to excavate. Conversely, softer mixes are easier for bees to tunnel into but are more susceptible to erosion.

Research on emergence box efficacy and long-term bee colonization of the modular bee hotels is ongoing. Using X-ray imaging, researchers established a non-invasive baseline to count living larvae inside nesting reeds before placing them in emergence boxes. Follow-up X-ray imaging and manual cocoon assessments quantify how wood type and microenvironment affect survival, mold, and emergence rates. Ground-nesting solitary bees often take several seasons or years to colonize new locations. Continuous monitoring will track whether ground-nesting bees establish nesting populations in the earthen blocks over subsequent seasons.

Looking Ahead

The five modular bee hotels are ongoing pollinator features on campus, serving as a model for scalable design. Research will continue, and techniques for creating earthen blocks will continue to be refined. The project may inform new guidelines on bee hotels.