Yuk. Glad we have no rats around here. Cockroaches are common in our area. Over the years, I’ve seen one or two slow moving ones around the house. But I have, every couple of years, sprinkled boric acid around. They take it back to their nests and it poisons them and any of their buddies it gets on. I also have a small open bag of food grade diatomaceous earth sitting next to my kitchen trash can. If any of them get in the house, chances are they’ll crawl over that stuff to climb up the trash can. It kills just by the m walking through it, because cockroaches groom themselve s, and it kills them when they lick it off, by causing them to dessicate. It’s probably healthy for mice, though. :( But it won’t hurt pets, whereas boric acid will.
Actually I read the boric acid kills them when they lick it off, while diatomaceous (do not breath it) kills by causing them to dessicate. We can eat it however if it is food grade.