Keen Hearing. The bat has advantage on Wisdom (Perception) checks that rely on hearing.   Recorded Mimicry. The bat can mimic any sound, including voices, it has heard in the last 24 hours. A creature that hears the sounds can tell they are imitations with a successful DC 12 Wisdom (Insight) check.   Some clockwork bats are created expressly to be familiars. Such creatures have the following trait.
Familiar. The bat can serve another creature as a familiar, forming a magical, telepathic bond with its willing master. While the two are bonded, the master can sense what the bat senses, as long as they are within 1 mile of each other.