You tip the restaurant server, the bartender, and perhaps the valet, but what about the person who cleaned your hotel bathroom and changed the sheets? Hotel housekeeping tips are easy to overlook because guests often never meet the worker who serviced their room. Unlike a restaurant check that practically forces a tipping decision, housekeeping usually happens while you’re out enjoying your trip. Yet current travel-etiquette guidance still considers tipping housekeeping customary in the United States, even as hotels have changed how frequently rooms receive service. All of that being said, here are eight things worth knowing about the people doing the work.