
I'm not entirely sure how they know as I'm the worse trainer handler etc on the planet... but after the first couple of days of being here and me standing on the boundary between myself and next door and sort of ushering them back onto our strip they haven't offered to leave it, even when the other neighbours are sunbathing on their grass and the usual birds etc. I can't say about an in season bitch as the only other dogs in this set up are males that have a run on their own garden, but yes as my male is entire if one of the neighbours bought a bitch then provisions would have to be made as an invisible boundary wouldn't exist then.
I will say that if the dogs are outside so am I, but that has always been the same even at the old property that had 5 ft fencing around the boundary (as in a typical garden). Unfortunately, too many scary Facebook posts have left me paranoid about having my dogs stolen from the garden. It's handy that our town park is literally 100yd by crow from the rear boundary, as in the houses that back onto the bottom of our gardens are facing the park
I don't think I have explained the layout all too well as I think it has come across as the gardens are available for everyone to get in. The only access to the gardens are through the houses (unless you scale the houses from one side, or 6 foot walls from the right and left side, or outhouses the back onto other people's gardens from the bottom). Imagine like a giant enclosed courtyard where a row of houses makes one wall of the enclosure, then strips that go from the back of each house makes their garden.
If anyone wishes to come and see how it actually looks then you are more than welcome, or if someone sends me an email address I can draw like an aerial view of it and send it via email. Maybe someone else will be able to describe it better than I can as i seem to be making a pigs ear of the way i describe it