The present invention relates to bait compositions containing a swellable agent (preferably swellable hydrophilic polymer) having a median particle size Dv50 of 100 μm and a phagostimulant for controlling a pest by physical effects (eg. rupture of organs or dessicating action), to methods for controlling a pest by physical effects employing said bait compositions and to the use of a swellable agent for controlling a pest ingesting said bait composition.