蜂

How it works

が (subject) points out 蜂(はち) (the bee) as the one doing the action — が (subject) is used here because it's presenting a fresh, observed fact rather than an established topic. 飛び回る(とびまわる) (fly around) is a compound verb: 飛ぶ(とぶ) (fly) fused with 回る(まわる) (go around), so it means flitting about all over.