Where did the term computer bug come from?
The story is that in 1946, when Hopper was released from active duty, she joined the Harvard Faculty at the Computation Laboratory where she continued her work on the Mark II and Mark III. Operators traced an error in the Mark II to a moth trapped in a relay, coining the term bug.
It came from the fact that the first computer was built with transistors that were the size of light bulbs. It is believed that this computer had its first malfunction due to an actual bug that died inside one of the transistors and they could not use it until they discovered the bug.