Time series of high-resolution white-light images of solar pores are analyzed. Granular motions in the vicinity of pores are driven by mesogranular flows: Motions toward the pore dominate in the 2 arcsec zone around the pore boundary, while at larger distances the granules move away from the pore. Triggered by these motions, small granules and granular fragments located close to the pore border penetrate into the pore, where they move inwards as short-lived bright features very similar to umbral dots. The formation of a transitory penumbra-like structure at the border of a large pore was observed simultaneously with a temporary reorganization of adjacent granular field to expanding elongated granules separated by dark filaments.