I have a niebour each side wit 2 cats each and one at the back with 1, and have had no bother, got 2 cat deter ants, both have sound and flashing lights, and one which give off a dog, barking, if I think I have had a visitor I set up my scarecrow water one, they sure don't like them, I would never go away and leave the loft open though just in case, link http://search2.virgi...t-search=Search home made repellent http://www.wikihow.com/Make-Homemade-Cat-Repellent