There are three types of foraging behaviour observed in the common starling . " Probing " involve the bird plunging its beak into the ground randomly and repetitively until an insect have been found , and is often accompanied by bill gaping where the bird open its beak in the soil to enlarge a hole . This behaviour , first described by Konrad Lorenz and given the German term zirkeln , is also used to create and widen holes in plastic garbage bags . It take time for young common starlings to perfect this technique , and because of this the diet of young birds will often contain fewer insects . " Hawking " is the capture of flying insects directly from the air , and " lunging " is the less common technique of striking forward to catch a moving invertebrate on the ground . Earthworms are caught by pulling from soil . Common starlings that have periods without access to food , or have a reduction in the hours of light available for feeding , compensate by increasing their body mass by the deposition of fat .