The Circulatory System

This part of a bat deserves some additional information.

A bat’s heart is extremely large relative to the body size. When scaled to match humans, it would generally be three times the size of a human heart! Heart rates can reach as high as 1400 beats per minute in some species, and as low as 20 beats per minute while in torpor.

They also have the unique ability to control the quantity of blood circulating in the wing at any particular time, by use of special shunts or valves. This allows blood to stay in the body during times of inactivity, thus reducing heat loss, or passing through the wings to help radiate heat during highly active times such as flying.