Aquatic animals adapted to polar climates, such as ice seals and penguins also take advantage of the slipperiness of ice and snow as part of their locomotion repertoire. Beavers are known to take advantage of a mud slick known as a "beaver slide" over a short distance when passing from land into a lake or pond. Human locomotion in mud is improved through the use of cleats. Some snakes use an unusual method of movement known as sidewinding on sand or loose soil. Animals caught in terrestrial mudflows are subject to involuntary locomotion; this may be beneficial to the distribution of species with limited locomotive range under their own power. There is less opportunity for passive locomotion on land than by sea or air, though parasitism (hitchhiking) is available toward this end, as in all other habitats.