A floor mat made of a rubber sheet having a top surface and a bottom surface with spaced-apart lugs extending therefrom, each lug having a pair of opposing nibs spaced-apart to define a passage therebetween with a longitudinal axis in a selected direction and the selected direction different from the direction of the longitudinal axis of the passage in an adjacent lug, which lugs cooperatively resist movement of the mat in response to loading by foot and wheeled cart traffic across the floor mat disposed on a floor surface.