The first recorded computer bug was an actual insect.
Why it is true
In 1947, Harvard engineers found a moth trapped in a relay of the Mark II computer, coining the term debugging.
Source: Smithsonian
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.