Hardly anyone now alive has not had a run-in of one kind or another with a malfunctioning computer—a garbled address label on a magazine, a dunning notice for a bill long paid, that sort of thing. Quite often, such mishaps are ascribed to “bugs,” those mythical insects that have inhabited the machinery of America for generations, making the term “getting the bugs out” a solidly entrenched part of the language.

But once upon a time there was a real bug in a computer—and not just any computer either: it was the Navy’s Mark II, one of the progenitors of modern computer technology. Navy Captain Grace Murray Hopper, the originator of electronic computer automatic programing and today with the Naval Data Automation Command in Washington, told the story recently in Annals of the History of Computing , a publication of the American Federation of Information Processing Societies:

“In the summer of 1945 we were building Mark II; we had to build it in an awful rush—it was wartime—out of components we could get our hands on. We were working in a World War I temporary building. It was a hot summer and there was no air-conditioning, so all the windows were open. Mark II stopped, and we were trying to get her going. We finally found the relay that had failed. Inside the relay … was a moth that had been beaten to death. … We got a pair of tweezers. Very carefully we took the moth out of the relay, put it in the logbook, and put Scotch tape over it.

“Now, Commander Howard Aiken had a habit of coming into the room and saying, ‘Are you making any numbers?’ We had to have an excuse when we weren’t making any numbers. From then on if we weren’t making any numbers, we told him that we were debugging the computer. To the best of my knowledge that’s where it started. I’m delighted to report that the first bug still exists; it is in the Naval Museum at the Naval Surface Weapons Center in Dahlgren, Virginia.”

Indeed it is; a photograph of the ill-fated creature is shown here.