There's another characteristic of raccoon behavior to consider. They have huge territories and rarely come back to the same food source on consecutive nights. They have multiple dens and make the rounds. If they killed a chicken, it might be a week before they return. If you are getting visitors nightly, it is likely different coons each night. In their original range, riverbottoms of what is now the Southeast US, the behavior of having large territories would prevent cleaning out all the food sources in one location.