I was so excited to have a little boy that is DD's age move in next door a couple of months ago. Now I find myself annoyed at this new family.

The flat part of our yard and the flat part of there yard is separated by their huge pool. For reasons I do not know, they allow their son to ride his power wheels on the sloped part of their yard, and he often crosses into our flat part. Not by a couple of inches but by six feet. Over and over again. I never see it happen, but I see the tire treads.

They also let their dog free range. It is in our yard a couple of times a week, to the point where when they clean up their yard they are half way into ours looking for messes.

I don't want their son to get hurt and sue me, and I don't want to step in dog poo.

How do I say stay the heck out of my yard? There is a very clear property line (like a little groove) so it isn't a matter of them not knowing where their yard ends.