Open up the floor registers and clean them out, this is not only good for your HVAC system, but also will reveal things like cigarette butts (unauthorized smoking), pet food (unauthorized pets), and the occasional kid toy (this is okay, since finding a barbie shoe or the missing lego will make a child happy.) 3.

My comment is that gravel may be a cheaper option, but gravel tracks and it will get on shoes etc and will track into the house and get all over the floors.....