The majority of loos weren’t connected to public sewers because, before the invention of the U-bend, rats and all sorts of other creatures would have run amok in people’s houses. One apocryphal tale from the Roman author Aelian describes how a giant octopus swam from the sea into the sewer and entered the house of a wealthy merchant in the Bay of Naples through the toilet, then proceeded to eat all the pickled fish in his pantry.