Hi. I read your suggested locations for the bumblebee houses but that paragraph doesn’t mention heat requirements or restrictions. Do the bumbles prefer a hotter house or a cooler one? I’ve seen males service a queen in my garden floor once and one was busy fanning her while the other was copulating with her. So, I’m thinking maybe a shaded location would be better, as they might run on the warm side, but then, what about the eggs needing more heat? You see my dilemma? Rather than buy two and put one in the shade and one in open sun to see which gets more populated, I’d rather just start with one. Also, I’m in a foggy part of San Francisco, and while I get a steady bumble visitation, the generally cooler temps here might warrant box placement on open-sun brick to keep their little internal equilibriums happy. With all this info, do you have any specific guidelines in this regard? Thanks so much! Yours is the only website I’ve found offering to ship well-constructed bumble houses. The scant few others I’ve seen only give building instructions on lesser-graded craft models.
There is no doubt temperature is important to both the young and adult bumblebees. And the behavior you noted is something that has been seen before. In fact, it appears as though the adults tend to build homes and nests where they won’t be as comfortable as possible but instead opt to build where it will be best suited for their young. Keep this in mind and place a single house where it will be warm enough for the offspring. Remember, adults have wings for “fanning” the extra heat away; the young are defenseless and though cared for by adults, do better when the default temps they like are most prevalent. That being said, an area that is protected but gets some direct sunlight will probably be best given the region in which you reside. Here in the south bumblebee nests are almost always underneath rocks, mulch or anything flat and shaded. Clearly our extreme temps are too much for even the young. I don’t think that will be a problem in San Francisco.