A form of locomotion of animals that live in and move through trees
Locomotion pertains to the various movements of species that propel them from one place to another. There are different forms of locomotion and arboreal locomotion is one of them; others are terrestrial locomotion and aquatic locomotion. Example of arboreal locomotion is climbing. Animals in trees do arboreal locomotion by clinging and climbing to trees. They have morphological and structural adaptations that enable them to move and spend most of their time hanging on trees. Some of the specializations are longer limbs, having claws, and highly mobile ankle joints.
Examples of animals showing arboreal locomotion are leopards, which are capable of carrying their prey up the tree to avoid competition from other predators, squirrels, and bats. Another is the tree snail that is exclusively arboreal. The earliest known tetrapod capable of climbing trees was Suminia, which is a synapsid of the late Permian.1
1 Jörg Fröbisch and Robert R. Reisz (2009). "The Late Permian herbivore Suminia and the early evolution of arboreality in terrestrial vertebrate ecosystems." Proceedings of the Royal Society B, [Link]