i have never heard of that! interesting.

one year, i had them nest inside the north wall of my shed. that was the year after i had loads of pollen plants for them: purple blooming and sunflowers.

i believe they prefer north for the cool and shade.

Watch them fly a ground hugging serpentine pattern as they sniff out old mouse nests to set up housekeeping in.
The fluff like dryer lint would be attractive to them if you put a wad of it in the pot.