In 1947, a relay in Harvard’s Mark II computer malfunctioned. The culprit? A moth wedged in the machinery. The team logged it in their notebook as the “first actual case of bug being found” — and taped the insect to the page. 

Though it was one of her team members who removed the moth, computer pioneer Grace Hopper helped popularize the story, and with it, the now-universal term “debugging.”