Why do I have roaches and how do I get rid of them?

-I have lived in my apartment for over three years and have never seen a roach but in this last week I have seen four. My apartment isn't dirty and I keep finding them in the bathroom around my shower except for one I found in my living room. I have a cat so I really want to avoid strong pesticides. The roaches are 1.5'' to 2'' long and have wings. They are also very quick. I catch them with a plastic cup and piece of paperboard and then flush them.I don't have roaches, but I did when I lived on the beach many years ago. Cleaning wasn't enough, esp. when you live in an apartment (I like things clean:) I did some research and came up with boric acid, which I put in all the crevices and windows...like a line right along where the carpet meets the wall...I mean a thin line everywhere. The roaches will eat it and take it back to their nest, and it ends up eradicating the whole nests over a month or so.Their environment somewhere nearby may have changed, forcing them to look for a better living environment. Try looking for their way into your apartment and sealing them up. Start under your sink in the bathroom and seal every tiny crack and hole that you see.
To get rid of them use plain cornmeal. Put about a teaspoon full in each corner of cabinets and drawers. They will be gone in a week or so.