Seeking a raccoon equilibrium

Our garage got ransacked. Everything was tossed everywhere, a terrible mess, and it wasn't all that neat to begin with. The culprit sort of signed their work in foot prints across Mrs. Phactor's windshield. Wildlife hanging around is no big deal for the Phactors' estate; it's got cover, food, and water, an urban oasis. Had TPP been more aware of our lodger, the door would have been left open so the intruder could have left the way they arrived. But it was late, after an evening of being well wined and dined so it wasn't until the next morning that the situation became clear. And so began the search for a raccoon equilibrium. The rear door was left open so our garage trasher could leave, but it also leaves open the possibility of another raccoon entering (or returning!). Somewhere there should be an equilibrium where the number of raccoons entering equals the number leaving, but from our perspective the idea is to hope that this equilibrium is such that TPP can close the door at one of those times when the number leaving is greater than the number entering. No idea how this is going so far, but the bird food container, a garbage can, might be an indicator.  If the lid stays on tonight, it should indicate that the raccoon comings and goings are exactly equal for now.