Intensity information is a strong cue for segmentation but on its own cannot be used to distinguish between accidental and non-accidental alignments in a scene, thus resulting in incorrect segmentations. However, motion information can be used to distinguish between accidental and non-accidental alignments. In this paper, an integrated method using both intensity and motion information for the segmentation and tracking of objects in a sequence is presented. The method is based on an extension to active contours (snakes) called spiders.