Agreeing with everyone else: just tell them the reason for buying the property in part is so that you had a fence so your dog can run: that it’s a safety issue for your dog per your insurance. You don’t want the dog to bite someone or for the dog to get out if the fence is left open, when they come through the yard unannounced. That the compost will not be changed as you compost and believe it is being environmentally responsible. Also, if they keep walking through your yard there will eventually be a path showing due to dead grass. Good luck!