Mckinley Presidential Library & Museum issued the following announcement on Oct 25.
How can bats hang upside down with out passing out?
A bat's circulatory systems pumps the opposite way — away from its head. Also, while all mammals have valves in their veins that prevent blood from flowing backward, bats possess these valves in their arteries, as well. All of these adaptations ensure blood is evenly distributed throughout the bat's body.
It also just happens to be more energy-efficient for bats to hang by their feet. As opposed to defying gravity and standing upright, no energy has to be expended while hanging due to the lightweight structure of their leg muscles and bones that were developed for flight.
Many bat species also sleep, mate, and even give birth while upside down. Additionally, because bats have short legs, they cannot form a running start to fly.
Instead, bats drop down from high places to gather enough speed to fly around. Hanging upside down also allows bats to hide from its predators, especially at night.
Original source can be found here.
Source: Mckinley Presidential Library & Museum
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