Abstract: A device (20) for deterring resting on a surface is disclosed. The device is formed from a planar sheet (10) having an elongate central portion (11) and two side portions (12, 13) joined to either side of the central portion; wherein at least one of the side portions contains an array of stabbing members (14); and wherein the side portions (12, 13) have means (16, 16?, 17? 17?) for joining one side portion (12) to another other side portion (13) once the side portions have been bent along their respective joins with the central portion (11) and abutted to each other.