What physical structure in bats functions as the fastest-contracting muscle known in any mammal?
Answer
The larynx
The larynx is the physical mechanism producing the rapid-fire calls, and it is the fastest-contracting muscle known in any mammal, capable of contracting 200 times per second.

Related Questions
How many species of bats exist globally?What is the process called when the common big-eared bat bombards a target with sonar to determine edibility?Which bat species emits the highest-pitched sound recorded for any animal?What strategy does the Pallas's long-tongued bat employ to evade prey that detects standard sonar?Approximately how quickly can the horseshoe bat alter the shape of its external ear structure?What physical structure in bats functions as the fastest-contracting muscle known in any mammal?What non-vocal method is used by some Old World fruit bats for navigation?What is the function of the 'special vocalization' used by bats within their social groups?According to the text, roughly how many species of fruit depend on bats for pollination?Why do juvenile bats sometimes attempt to drink from smooth, non-liquid plates placed in the jungle?