When I rescued these bird houses, the backyard owner had these bird houses - one on a post around 4" high, and the other over a door way, in full afternoon sun. When I brought them into my yard, I hung them on a fence facing south, that got half a day of sun. The bumbles lived in the bird house until mid-summer, and then flew away, as is normal. When I opened the bird houses, they had some soft, fluffy material in there. Not sure who put them in there. But I thought I would harvest the fluffy seed pods from late winter blooming anemones, which I have seen humming birds harvest - probably for nest building. But I would think any type of fluffy seed pod should do ie. milkweed, or thistles/artichokes. So I'm going to put one house back on my fence, and one house in the shade and see what the bumbles like.
The website says bumble bees like shady spots, but my bumbles seemed to do fine with a half day of sun. So let me know if you'd like a couple of bumble bee houses. Yolanda