 Similarly, its nostrils are very small to keep all of the sand out of its nose and lungs.X-ray imaging has demonstrated the lizard swims within sand using an undulatory gait with its limbs tucked against its sides rather than use its limbs as paddles  to propel itself forward.Subsequent studies of the mathematics of sandfish sand-swimming, using robotic models, and electromyography show that the sandfish uses the optimum waveform to move through the sand with minimal energetic cost, given its anatomy.