سؤال 21 — Short Reading 21 — Main Idea

A community science group placed small bee hotels in several city parks. These wooden structures contain narrow tubes where some solitary bee species can build nests. Unlike honeybees, many solitary bees do not live in large colonies or produce honey. The project team checks the hotels monthly and records which tubes are occupied. The aim is to learn which park conditions support native pollinators and to teach residents that cities can provide useful habitat for many insects.
What is the project mainly trying to learn?