Stunning pictures, but I can't help but make a small correction. The "bees" are not bees, but flies. They are sometimes called sweat bees and often hover around people, who swat at them thinking them to be bees, but they are syrphid flies, also called hover flies, belonging to the family Syrphidae. Some of the larvae (maggots) of these flies live in water, feeding on decaying plant material. The adults feed on nectar and pollen. I have their larvae in my aquatics collection from graduate school. Sorry, as a biologist, I couldn't help making that distinction.