Nearly every building, including private homes, has a vestibule to act as a buffer between the outside and inside. Where hygiene is a concern, such as medical buildings and restaurants, a washing pool is found here, as shown in Table Manners and Everybody Poops Together. Otherwise, there is a bristly floor mat for wiping the paws off before entering. Humans are expected to remove any outer footwear and leave it in the vestibule. On orbital colonies, the vestibule is an airlock separating the detachable habitation module from the hull of the colony.