The first computer 'bug' was a literal moth.
Why it is true
In 1947, engineers found a moth trapped in a relay of the Harvard Mark II computer, causing a malfunction. They taped it to the logbook.
Source: Computer History
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.