I thought you might like to know that the first computer bug is still in existence. We were building Mark II the summer of 1945. It was a hot summer in Cambridge, and naturally since it was World War II we were working in a World War I temporary building. Air conditioning wasn’t very good, no screens, and Mark II stopped. We finally located the failing relay, it was one of the big signal relays, and inside the relay, beaten to death by the relay contacts, was a moth about this big.

So the operator got a pair of tweezers and very carefully fished the moth out of the relay, put it in the log book, and put scotch tape over it. And below it he wrote, “first actual bug found”.

I knew you’d be glad to know that the bug is still in the log book under the scotch tape. It’s in the museum at the Naval Surface Weapons Center at Dahlgren, Virginia.

— Capt. Grace Hopper, Future Possibilities: Data, Hardware, Software, and People, 1982, National Security Agency