I noticed a bombus hypnorum queen near a bramble patch on a peat moor in the Somerset levels last week. It was flying low to the ground and then, over a period of several seconds, it disappeared into a tiny hole in a south facing bank. I assumed it was thinking about hibernating there. The soil was obviously noticeably quite loose, a bit like the spoil from a mole burrow and I could actually see it shift somewhat as the bumblebee moved around inside. After about a couple of minutes it emerged and flew off. SO, not hibernating there - or not yet, anyway.
Is this typical behaviour of new queens trying to find a hibernation spot?
What a fascinating observation !
Like you I presume that the bee was attempting to dig herself a hibernaculum.
A year or three back I saw a B. lapidarius queen do something similar. It was around August. She was digging in loose earth beside the roots of a fallen tree. It was beside a path in the wood behind my house, on a west facing slope. Fairly quickly I suspect that she hit a stone, because when I looked later she had given up and gone.
From memory Alford’s big book Bumblebees has some observations of queens choice of hibernation sites.