Aspects of a lawnmower and in particular a robotic lawnmower are disclosed herein. Specifically, the lawnmower may include a passive cleaning assembly for removing detritus from the housing, the passive cleaning assembly being moveably mounted on said housing. Movement of the lawnmower with respect to the ground may cause a cleaning portion of the passive cleaning assembly to move with respect to the housing and thereby remove detritus from the housing. In one aspect, the lawnmower may be configured such that, during use, the cleaning assembly is moved with respect to the housing thereby causing a scraping edge of a cleaning portion of the cleaning assembly to move with respect to the housing and thereby scrape detritus off the housing. In another aspect the lawnmower may comprise a sliding member having a ground-engaging surface that is positioned so as to face towards and to slide over the ground during such movement of the lawnmower over the lawn. In another aspect the lawnmower may comprise a ground contact footprint being defined by a polygon bounding a plurality of ground contact regions. In addition, at least part of one or more of the cutting areas swept out by the grass cutting blades may be positioned beyond the perimeter of the ground contact footprint, at the front of the lawnmower with respect to its forwards direction of movement.