Okay I am going to toss this out here for the heck of it.............What if they are bee boxes and you find out that your county has no problem with folks having bee hives in their back yards. Now what do you do? And I noticed that the neighbor friend of yours suggested that you call the county and report them, didnt that raise the red flag for you?
You need to see where you stand before you call the county because it can really backfire on you. From what I can tell they can see in your yard as easily as you can theirs and if they find out it was you that called they can watch you like a hawk until you drop the ball. I know in my county if you have a swimming pool you have to have a separate fence going around the pool to keep short folks from sneaking in and drowning. And it has to be a privacy type of fence if you can see it from another property or the street. Also if you have the pool or an out building to close to the property line they will make you move it. My neighbor is retired from code enforcement here in our county and he said that if a whiny neighbor called in about something trivial that he would look to see if they were breaking any rules and make them have to fix the problems on their property for wasting his time.
I will tell you like I used to tell my district managers all of the time, "When the $&@% hits the fan it is never evenly distributed"
Billy