Unfortunately, cats breed like cats; which is worse than rabbits. And so many people are willing to share their homes with unspayed female cats. I don't know how anybody does it. When my mom first adopted Pixel and she wasn't spayed she drove us nuts for weeks until the appointment. We weren't sure if her last owners had her spayed or not until her annoyingness answered the question. I know somebody who had 6 unspayed females. How does anyone do it? I don't think too many cats get adopted either. People give kittens away for free by the dozens. That's a whole lot more motivation to the average person than spending money adopting. In my area, they have free or discount adoption days for cats all the time just to try and move them to homes before they're put down. I don't know how anybody gives up their animals like a piece of used furniture though. People are heartless.