Hello Jean, as I understand it it is all about territory and setting out boundaries, The famliy next door can barely look after themselves so lord knows why they want four cats. I used to have dozens of wild birds visiting the garden, blue tits used the nest boxes every year and we could watch them fetching food for the young for days on end, then they would all be gone for another year. We would see them feeding from the bird table but they had left the nest box. I still have a couple of robins and whenever I am working in the garden they are always near to me. They will almost take a small worm out of my hand but I have to put it on the ground for them to take it. They will come closer than a foot away.