The term computer bug originated when a moth got stuck in a computer in 1947.
Why it is true
In 1947, a team of researchers found a moth stuck inside a primitive computer. The creature was removed and taped into the logbook with the note first actual case of bug being found, popularising the term.
Source: MIT
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.