“Idle hands work for Hitler!” Thousands of posters declared in World War II-era America. “Our boys need sox! Knit your bit!” Mid-1940s propaganda aimed at women back home was typically used to encourage female involvement in war efforts through domestic craftsmanship and economic stimulation in the absence of male workers. Women who made clothes to be sent overseas in care packages or who filled the factory positions left vacant by newly enlisted soldiers were rewarded with the feeling that they had directly supported the war efforts and a new kind of independence; it was an extremely effective tactic of mobilizing an entire class of Americans who had scarcely ever been considered in previous wars. Knitting had long since been established as a distinctly female-coded activity, but World Wars I and II adapted it from a useful hobby into a patriotic, goal-oriented pastime. Knitting clubs soared in popularity as women across the country eagerly produced socks, hats, scarves, and sweaters for soldiers abroad, encouraged by such public figures as Eleanor Roosevelt, who promoted Knit for Defense tea gatherings and was frequently photographed with a knitting bag in hand during the war. Knitting gave countless women a very immediate sense of involvement in the war efforts and boosted national morale considerably. However, some women gave the mantra “knit your bit” an entirely different meaning. Instead of socks and sweaters, female spies knitted hidden messages or codes, which they then transmitted across enemy lines disguised as simple balls of yarn or knitted fabric. This type of encoding is known as steganography, defined by Oxford Languages as “the practice of concealing messages or information within other nonsecret text or data”. There are several methods through which messages can be sent in knitting; in its standard form, knitting is binary, made up of stitches called knit and purl. Therefore, knitting lends itself perfectly to binary codes such as Morse code. If stitched correctly, a garment as simple as a hat or a scarf can contain elaborate and lengthy messages. Knitters can also use Morse code in the form of knots (by tying knots in their yarn in sets of one and two to represent dots and dashes or by varying the distances between knots) and then either pass the encoded ball of yarn across enemy lines or knit the knots into an item to be unraveled and decoded upon interception. Modern knitters have also devised various other techniques of concealing hidden meaning in their knitted crafts, such as corresponding letters to the number of rows in a certain color, but these were not popular among knitting spies.
When women were recruited as spies, it was typically done with the intention of avoiding suspicion. Male spies were far more common, and in times of war, men who were foreigners were especially conspicuous. Women, by comparison, were paid little mind, especially if they were busy with innocuous activities like knitting. Some governments used this presumption to their advantage; most famously, the British government employed Phyllis Latour Doyle to infiltrate the German army and send coded messages back in her knitting. Doyle joined the British forces in 1941 as a flight mechanic, then trained as a spy for several years before being parachuted into Nazi-occupied Normandy, where she posed as a French tourist and spent several months exploring the region by bicycle. Throughout this journey, she coded over 100 messages into her knitting and passed it on to British intelligence officers. Many of the men who had been sent as spies before her had been captured or executed, and it was by virtue of both her womanhood and her knitting that she remained undetected. The British government was not alone in its employment of women to remain inconspicuous; likewise, the Belgian Resistance used knitting women to conduct espionage, taking advantage of the combined stereotypes of the harmless natures of women and knitting. Women in this movement would sit near train yards to do their knitting and incorporate previously agreed-upon codes, such as dropping a stitch to indicate a certain kind of passing train or purling a stitch to represent a different type of transport. These codes kept the Belgian Resistance informed of the schedules and modes of transport their enemies were using, all under the cover of old women simply knitting scarves. In fact, this manner of code transmission became common enough that the U.S. Office of Censorship banned the posting of knitting patterns abroad for fear that the letters would contain some secret code indecipherable to those who did not knit. Even today, knitting patterns range from relatively simple to wildly complex, and the slew of seemingly random letters and abbreviations that make up the instructions can, to the untrained eye, appear disconcertingly similar to code.
Although this is where the most famous examples originated, the practice of using knitting to disguise code was not unique to World War II. Knitters in earlier times may not have incorporated their messages directly into their crafts, but knitting as a cover for eavesdropping or smuggling information in knitting bags was an effective espionage strategy nonetheless. This was a popular tactic as far back as the Revolutionary War; a woman named Molly Rinker, for example, listened in on the conversations of the British soldiers quartered in her home and recorded what she heard on a piece of paper which she would wrap up in a ball of yarn. She would then take her knitting to a predetermined location, drop her yarn, and leave it for a revolutionary to pick up. Knitting may seem an unlikely suspect for covert communication and illegal activity, but historically, it has played a remarkably central role in women’s subversions of expectations and acquisition of agency. When international conflicts assigned women needles and yarn instead of uniforms and guns, they took them up as weapons regardless and used them to change the course of history, whether by providing soldiers with clothes to remind them of what waited for them back home or by stealing closely guarded secrets under threat of death and the pretense of simply “knitting their bit”.