Halloween: the mystery of the black cat

Today daughter #1 and I collected Violet early from nursery so that she would be ready to greet the trick or treaters with our ample supply of treats.  She was already dressed in her Halloween black cat outfit (although she refused to wear the ears!) as you see in my picture here.
We always decorate our porch with carved pumpkins, (LED) tea lights and spooky spiders etc to show that we are a friendly house  to those out trick or treating: we are never disappointed and always receive a number of beautifully dressed up youngsters, often accompanied by parents standing back at a discreet distance.
This year, though we had an unexpected visitor: the little black cat in my blip arrived with a group of children and quietly slipped into our house...where he proceeded to have a good look round every downstairs room, completely unafraid, before taking his leave.  We have never seen this cat before and it being Halloween, wonder if we will ever see him again....