>>I often saw swarms living in bushes. I figured they simply gave up looking for a suitable place and stayed where they were. 

I good size swarm in favorable weather, if it does not pick a nest site in the first few days, will often build a small comb where it landed and the queen will start laying eggs.  Once eggs and larvae are present, the bees shift from nest hunting to nectar/pollen hunting.

I've removed several swarms from bushes to find a small comb attached to a branch.

Waldemar

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