Arboreal locomotion small branches, as they may wrap too far around and prick the animal's own paw. Adhesion is an alternative to claws, which works best on smooth surfaces. Wet adhesion is common in tree frogs and arboreal salamanders, and functions either by suction or by capillary adhesion. Dry adhesion is best typified by the specialized toes of geckos, which use van der Waals forces to adhere to many substrates, even glass. Frictional gripping is used by primates, relying upon hairless fingertips. Squeezing the branch between the fingertips generates a frictional force that holds the animal's hand to the branch. However, this
Mars habitat addition to the reactants. Mars habitat A Mars habitat is a place that humans can live in on Mars. Mars habitats must contend with surface conditions that include almost no oxygen in the air, extreme cold, low pressure, and high radiation. Alternatively, the habitat may be placed underground, which helps solve some problems but creates new difficulties. One challenge is the extreme cost of building materials for Mars, which by the 2010s was estimated be about $2 million USD per brick to the surface of Mars. While the gravity on Mars is lower than that on Earth, there is increased