jessmullins's Identifications

Four individuals have been regularly returning to the same clump of grass to sleep each evening after foraging amongst the wildflowers in my yard. The yard is covered in native grasses but they always return to the exact spot, and three of them always sleep very close together on the same grass stalk while the fourth one chooses to sleep about 12" away, almost as if it's the designated sentry. Absolutely fascinating. If anyone can explain their behavior I'd love to learn more about this bumblebee species!

(Update: one month later, one bee is still returning each evening to sleep in the same spot)