So several scenarios emerge. If the core territory is threatened by being overlooked or invaded by cats that are not part of the group, then the boundary of the core territory can retreat into the house and the resident cat[s] will use spray or claw marks to delineate a boundary at the edge of the core territory which happens to be within the home. These cats may end up inhabiting the upper rooms of a house as core territory and then spray marking or middening on the ground floor, but the situation often starts when urine marks appear at windows or external doors, or around the cat flap. | So several scenarios emerge. If the core territory is threatened by being overlooked or invaded by cats that are not part of the group, then the boundary of the core territory can retreat into the house and the resident cat[s] will use spray or claw marks to delineate a boundary at the edge of the core territory which happens to be within the home. These cats may end up inhabiting the upper rooms of a house as core territory and then spray marking or middening on the ground floor, but the situation often starts when urine marks appear at windows or external doors, or around the cat flap. |