It’s pretty common to find a mouse nest in beekeeping equipment. What isn’t common is the knowledge that bumblebees love to use abandoned mouse nests as their own nesting sites come spring time. This is why bumblebee nests are often underground, but I’ve also removed them from garages (under a pile of rags), and under garden ornaments; anywhere they can “sniff out” an old mouse nest. I happen to think bumblebees are pretty interesting to watch, so whenever possible, I make bumblebee nest boxes, and this is how I do it.
I always keep my eyes open for cheap birdhouses at yard sales and flea markets. The one pictured was three dollars. I simply place the mouse nest inside, and combine it with some saved up dryer lint. Some people use flower pots instead of birdhouses, but I’ve never had success with those.
The last step is, ironically, to keep birds out. So I cover the entrance with mesh. If it smells sufficiently mousy, a mother bumblebee will find it wherever you put it. I think I will put this one right outside a window.
One of my nest boxes from last year was too slick, and too small. It was eventually occupied, but the colony never flourished. View the problem here.