Your house has been marked or either that kitty belongs to you and you just don't know it yet. I had one that sat on my doorstep for 2 years BEGGING to be mine. She had a owner that found her on my doorstep one day when I wasn't at home and claimed her for her own but mistreated and neglected her. It took me 2 years to talk that neighbor into giving her to me but she finally did and we have lived happily ever since. Samantha adores me and I adore her. She has the sweetiest soul of any cat I have ever met. (she is the blackie in my siggy)