Morse code was developed in the 1830s and 1840s as a system of dots and dashes for sending messages over telegraph wires, later becoming standard for radio and emergency signals. Online, its serious beeping has been repurposed as comedy shorthand for secret communication, especially in the cat morse code meme format where animals look like they are transmitting a plan. The clip stays popular because viewers instantly recognise the pattern as a hidden message, even without decoding it, making it useful for short meme edits.