How do bats use their thumbs for climbing and handling food?

In bats, the thumb is distinct from the rest of the fingers because it remains free of the wing membrane and is typically equipped with a claw. These anatomical features allow bats to utilize their thumbs in several ways:12

• Climbing and Locomotion: Many bat species use their thumbs, often in conjunction with their wrists and hind feet, to walk or crawl across horizontal and vertical surfaces. Some species, such as certain Old World fruit bats, use their thumb claws to crawl along branches in a slothlike posture. Others, like sheath-tailed and mouse-tailed bats, prop their thumbs and wrists against surfaces to scramble rapidly in various directions. Additionally, bats that walk on smooth surfaces, such as leaves or bamboo, may possess specialized pads or suction disks on their thumbs or wrists to assist with movement and roosting.31
• Handling Food: In some species, the thumb is specifically utilized for the manipulation and handling of food.1

Furthermore, the thumb serves other functional roles; for example, many female bats use their thumbs to suspend themselves in a hammock-like fashion while giving birth.1