Where the load builds Family rooms and pet paths carry most of the bacteria
Bacterial load on carpet is not even across the room. It builds in the spots feet hit every day, the rug under the coffee table, the path from the back door to the couch, the corner where the dog sleeps, and the strip in front of the kitchen. Those zones see skin cells, food crumbs, pet saliva, and outside soil tracked in from the yard.
After cold and flu season runs through the house the same zones are where droplets land and settle into the fibers. A regular cleaning resets the soil load, and a sanitizer step on top of it knocks down the bacteria that the cleaning leaves behind.
We see this most on requests around the change of season, after a holiday week with family in town, and on rental turns where we have no idea what the last household brought in.