Chasing usually involves running at full speed after a prey item, moving object or individual. All senses are centred on the subject: thus ears are directed forward, eyes are wide and focussed and the whiskers are usually flexed outwards away from the face and slightly forward. During a chase, the cat may change direction quickly depending on the direction in which the subject moves.
Chase is further described in social behaviour, predatory behaviour and play.
The following video illustrates two cats chasing a toy mouse.