I'm also amazed at the number of house cats that are left alone. In my neighborhood people move in and out often and sometimes they leave behind their cats. I can't understand that, my parents taught me that pets are part of the family. They could at least try to find a home for their cat, but they just leave them on the street. That's how I ended up with so many porch cats. I take care of all the friendly cats that people have left behind.