These mining bees nest in colonies in the ground around the bases of Norway maple trees in a grassy area of Cobbs Hill Park. They emerge in April around the time that the trees flower, and I suspect that this might be a significant association. They also forage in the flowers. Photo #1 shows one part way out of its burrow. They were in almost constant motion, so I despaired of getting a clear picture. However, I stumbled on some interesting behavior that enabled me to get clear photos. I observed one female being repeatedly attacked and possibly stung by at least one other. The victim seemed stunned and almost immobile. This immobility enabled me to get some clear photos (#s 2 , 3 ). Photo #4 shows a pair mating. The smaller one on top is presumably the male. Photo #5 shows a female foraging in a maple flower. Although I was surrounded by the bees and even kneeled among them, they showed no inclination to sting me. Since Norway maples are an introduced species, I wonder if the bee is also an introduced species.