Carpet stains reappear if they were not thoroughly removed during the first treatment. Carpet fibers are long and dense, so the stain can seep down into the lower part of the fibers and then wick back to the surface if it's not removed completely. Make sure that the stain remover you choose penetrates and saturates the fibers all the way down to the carpet backing before you blot it up. For more information, check out our thorough guide on how to remove stains from carpet.