The Origin of the ‘Computer Bug’ (Yes, It Was a Real Insect)

When we talk about computer bugs, we usually mean frustrating glitches in software or systems. But did you know that the very first documented “bug” in computer history was not a metaphor—it was an actual insect?

A Strange Day in 1947

On September 9, 1947, engineers working on the Harvard Mark II, one of the earliest electromechanical computers, encountered a mysterious malfunction. After some investigation, they opened the machine’s panels and discovered the culprit: a moth trapped between relay contacts, preventing the system from working properly.

The operators carefully removed the insect, taped it into the logbook, and humorously labeled the incident as the “first actual case of a bug being found.” The logbook entry is still preserved today at the Smithsonian Institution.

From Moth to Modern “Bugs”

The term bug had been informally used in engineering long before this event, but the Harvard Mark II incident made it iconic in the world of computing. Since then, every software glitch, hardware fault, or unexpected system behavior has been referred to as a “bug.”

Why This Matters

The story of the moth is more than just a quirky piece of tech trivia. It reminds us that technology is built in the real world, where even something as small as an insect can bring down a giant machine. Today’s bugs may be buried deep in millions of lines of code, but the legacy of that literal moth lives on every time a developer says, “We need to fix this bug.”