A Flying-fox's arm and hand bones are similar to our hands, with four fingers and an elongated thumb. On the end of the thumb is a hook which is a very important tool. They use this hook to invert when they go to the toilet, as a defensive weapon and they can climb using their thumb hooks. The hook is also useful to bring food sources closer within reach.
Flying-fox bones are very light and their upper bodies very muscular to enable flight. These adaptations have meant they cannot stand upright and so they must hang by their feet. This requires little effort due to leg tendons that 'lock' the claws in place on the branch.
Flying-fox skeleton © Louise Saunders