Africanized bees are no more aggressive than any other bee unless they are near their hive. If they're off foraging away from home, they're fine. I have never heard of bees nesting underground-was it a regular, honeybee type of bee or a wasp? At the house I lived in previously we had yellow wasps that nested underground, and it seemed like they had holes all over the entire yard. They were very non-aggressive, though, and even though we were walking over their nest all the time, and had dogs back there running around, they never stung anyone. We have them at this house too, but I don't know where they are nesting. They're landing on the pool all the time getting water, but again, not at all dangerous.

There are hundreds of different species of native bees in Arizona. Almost all have a solitary lifestyle and most nest underground. Here's a wordy but useful link: Bees

Alkali bees live underground. You would really have to work hard to piss them off and have a female sting you. Even then they are about the least painful sting there is.

If it hovered though I suspect it is a hoverfly and why they do the crazy antics they do you'd have to ask them. Maybe it thought you were cute.

Thanks for all the great info. So there ARE underground bees! Now I feel bad that I likely destroyed the entry to his home.

I have seen the hoverflies, but not any this year yet. This was definitely a bee.

Fun discussion! I've seen some of those solitary and semi-solitary bees going into holes (doors? hah) in the ground too. I haven't heard of some of their specific names so thanks for mentioning it. I'll be sure to continue leaving them alone.