Just found out my neighbours across the road from me have stuck cocktail sticks in their newly laid gravel at the front of their house. Local cats have been using the stones as a toilet. It's really upsetting me. I have two cats. I'm really concerned that an animal is really going to get hurt. I don't know these neighbours very well, they only come down at weekends. I just can't get over what they've done. What should I do?