Where Are These Cats Coming From?

Yes, we have cats. They are indoor/outdoor cats depending upon what side of the door they are on at any particular moment. We had two, but with the passing of my Father-In-Law we accepted his pet into our home as well.

All our cats are neutered so there is nothing with sex pheromones going on and we never have food for them outside, but suddenly all the neighbor cats come visiting on a regular basis. There is a black and white one that shows up and looks in through the living room door window. Then there is a mackerel tabby that sits by the garage occasionally. Then all of a sudden this ginger cat has been hanging out. I have no idea where they are coming from or where they go when they leave here.

You'd think our cats would be territorial and run then off, but no, they hang out with them when they are outdoors. It's a good thing we don't have a pet door or there would be cat parties in here.