A mat (20) for overlaying one or more elongate slats (16) of a slatted floor (10) of an animal house has an upper surface (34) to bear the weight of an animal and a lower surface for overlaying the slatted floor. A plurality of edges (28) run along a lengthwise direction defined in use by the elongate direction of a slat on which the mat is to be laid. The upper surface comprises a plurality of upper surface segments (36) disposed at intervals along the lengthwise direction, and a plurality of drainage channels (38) are provided between adjacent upper surface segments. The drainage channels are open to the upper surface and slope downwardly towards an edge to assist in run-off of waste from the mat. The upper surface segments are provided with a convex profile such that waste is encouraged to drain from the convex upper surface profile via an edge of the mat either directly or via a drainage channel.
