One of my neighbours has installed one of those “undetectable to the human ear” cat deterrents. Trouble is I and some of my neighbours can hear the bloody thing. It’s obviously motion sensing but seems to sense the movement of a blade of grass. It’s so loud and like Chinese water torture. It’s boiling but can’t open my windows. I can tell roughly what direction and can’t be that far. Should I just knock, am I being unreasonable to ask them to switch it off, it’s starting to give me a migraine.