The most interesting hover fly was this one though. When it flew in I thought, "Why does that bumble bee sound so weird?" But it wasn't a bumble bee, it was a king of Batesian mimicry! Look at how closely this fly resembles our Eastern bumble bees and carpenter bees! It even has a little spot on its back and hair on its legs that look like pollen baskets. But bees don't sit around on flowers and wash their hands!
I'm pretty sure the species is
Mallota posticata.
When I was researching them, I found out that they lay their eggs in standing water in holes in trees, and their larvae have little tubes that they stick above the water to breathe like a scuba diver!