Where does the term "bug" come from?

There's a story of a Harvard Mark II machine in which

on September 9, 1947, a moth got stuck in the relay.

The moth got carbonized and then caused a short circuit in the machine,

which caused the machine to break.

Technicians retrieved the moth from the relay and this was then recorded

as the first bug actually being found in a computer.

The bug is now on display at the Smithsonian in Washington.

The term "bug" as you can see was already known in 1947, and it's actually much older than that.

You can even trace it back to Shakespeare who used the term in order to

describe some form of spector sitting on the chest of people in the night and causing them nightmares.