Aside from keeping them penned up any ideas? We live out in the country, we have a good relationship with our neighbor, unless the roosters have an issue with each other we don't really have any problem with his chickens coming on our property or vice versa.I think your neighbor needs to keep his rooster in his own yard.I don't know the laws where you live but around here we dispatch animals domestic or wild that are a danger to our own. That being said Id suggest you talk to your neighbor first about the situation.