Animal house

An animal house defining an interior region and an exterior region, the animal house comprising:

• an impermeable hollow-moulded structure having at least one convex surface, a first flat surface extending in a first direction and a second flat surface facing the exterior region, the second flat surface extending in a second direction and defining a plane, the at least one convex surface connecting the first flat surface to the second flat surface;
• a top wall connected to an outer wall and to an inner wall, the top wall defining a first gap with the at least one convex surface, wherein the top wall is moveable laterally with respect to the at least one convex surface and is not restrained for movement by the impermeable hollow-moulded structure;
• a rib defining a sharp edge wherein the rib terminates in the sharp edge and the sharp edge terminates proximate to the plane of the second flat surface;
• and
• wherein the rib is adapted to be releasably attached proximate to or on the at least one convex surface such that the rib diverts a liquid flowing over the at least one convex surface away from the second flat surface and away from the first gap.