Write a short note to your neighbor with your contact information on it….. Tell them that you want to exchange phone numbers in case you ever have to call in a tracking dog and the deer crosses the line. Put the note in a zip lock baggie and hang it on their gate with a piece of duct tape. In most cases it will be just that easy. It may even be a good ice breaker to forming long term relationships with your neighbor. It seems like very few people know their neighbors.