Even though my next door neighbor has 30 chickens at their summer home, we have a good relationship for the last two decades, I still would not allow my chickens to wander over to their yard, potentially scratched up their lawn in seconds, destroy their flower beds, and poop on their property. It is just basic courtesy.
If you can't put up a fence, either train your chickens to stay on your property, or stand guard to keep them confine to your lot, or lock them up in their run.
If you can't put up a fence, either train your chickens to stay on your property, or stand guard to keep them confine to your lot, or lock them up in their run.