I do find it strange that the grandparents let him run amuck like that. That is how children learn rules after all, by stepping in and actually enforcing them. I can't imagine why they would allow him to break the rules. It could be that they are animal "stupid" and have no concept that chasing animals is wrong. Clearly Damian does not. Could you allow him to look at the animals through the fence? Tell him that you love how much he loves the animals, but no one likes to be chased around scared, and tell him that you only let people in with the animals that can follow the rules? It sounds like you really like the grandparents, and would like to try to be nice to the boy, but if the adults in his life are not going to enforce the rules that you have stated to them... I don't know, that would be a very sticky situation. I don't think you are confrontational by nature (I know I am not) And it sounds like you are tryiong to take the gentlest route possible without terrifying the animal family. Sometimes a small child's love can be turned into masochistic terror (for the animals) If unreigned, but you'd think at age 4 he would have learned proper etiquette. I feel for you. Some of my neighbors let there children run amuck, I've found a 3 year old child in my sheep pen once. (that wasn't my child)