All sorts of things could kill people in exactly the right circumstances. A handful of people have probably died after losing control of their vehicle swerving around someone's dog that wandered into the street. Just because something can add the final straw to a situation causing a bad thing to happen doesn't mean the likelihood is high enough to be worth regulation.

Considering how many drones are in operation ans how many accidents haven't happen I think we should err toward no license required under a certain altitude over private property (the same altitude at which you need to put a red light on a structure in that area sounds like a food starting point).

Lots of people have died avoiding animals. Slow down, honk your horn, and keep driving under control.

And yet we don't require licenses in order to have most common pets...

Don't most cities and towns require dog licenses? That seems like a fairly common pet and I know we have to get a license.

I live in one of the most busybody states on the east coast and I've never heard of a city or town that required a license for a pet.

It’s extremely common to require dog licenses. My rural New England town does.

You could kill someone by playing football near a helipad too, should we heavily regulate playing football everywhere too?