The saying "like a bat out of hell" has been common in the UK
for decades. It means to leave a place quickly. Bats fly very
quickly and erractically, often looking like they are in a
panic.
The phrase "like a bat out of hell" first appeared in print in
1921 - legend has it that WWI plane fighters used it to describe
flying at top speed. So why "out of hell"? Bats have long been
associated with the occult, so the out of hell phrase was
apparently added for extra flavor.
The phrase also became popular in the US after the 1977 release
of the Meat Loaf album, "Bat Out of Hell."