Here's why your pants have a teeny tiny pocket that's too small to use

• The tiny pockets on jeans and some other pants were designed for pocket watches.
• They were first used with the original Levi's "waist overalls" jeans in 1890.
• People don't use pocket watches anymore, but the pockets are still around.

Ever notice those little pockets on your jeans?

They're pretty much too small to be useless. But in ye olden times, it had an important purpose: The pocket held a pocket watch.

The ubiquity of the pockets can be traced back to the design for "waist overalls," the original name for the blue jeans made by Levi Strauss & Co. They appear on the design in the patent Strauss and J.W. Davis received for "Improvement in Fastening Pocket Openings," way back on May 20, 1873, and were first put into mass use in 1890 with the "Lot 501" jeans, the model for Levis 501 jeans today.

"The watch pocket was a feature of our first waist overalls," Tracey Panek, the in-house historian at Levi Strauss & Co., told INSIDER in an email. "The oldest pair of waist overalls in the Levi Strauss & Co. Archives [from 1879] includes the watch pocket."

Because the small pocket was meant to hold pocket watches, you won't usually find it on suit pants. Suit jackets already have pocket watches, which makes one on the pants superfluous. Levis Strauss himself, for example, kept a pocket watch in the vest of his business suit, according to Panek.

Pants with the tiny pocket are called "five-pocket pants," but the tiny pocket isn't actually the fifth one. The fifth pocket is actually on the back-left, added to Levi's 501 jeans in 1901.

"Our 19th century overalls had a single back pocket on right side of the pant beneath the leather patch," Panek said. "It was riveted in the top two corners and included our recognizable arch design, called the Arcuate, stitched with a single needle sewing machine."

They're all but useless today.

Pretty much no one today carries around a pocket watch. People tend to check the time on their phones or wristwatches. Panek told INSIDER that the small pockets are kept on Levi's jeans today to maintain the integrity of the original design.

"The watch pocket was an original element of our blue jeans, like the rivets on our pockets, button fly, arched back pocket stitching and leather patch," Panek said. "To preserve the integrity of the early design, Levi Strauss & Co. maintains the watch pocket."

Other pants have the pocket as an homage to the pocket watch. The style gives pants a more casual look because they don't look like they're meant to be matched with a jacket.

Different brands put the small pocket in different spots. Some put it in the front, next to a bigger pocket. Others have a smaller pocket within the regular-sized side pocket.

But for Levi's jeans, they've remained essentially unchanged since the 19th century. One exception, Panek told INSIDER, was during World War II.

"One interesting fact about the watch pocket is that during WWII the two corner rivets were removed as a way to conserve metal for the war effort," Panek said. "The rivets returned to the watch pocket after the war."

Today, there isn't much you can do with the tiny pocket. Some people suggest using them to keep coins or keys, but they tend to dig into your hip. Others recommend them for matches, condoms, and tickets, but  those are difficult to extract if your fingers aren't similarly tiny. The pockets are somewhat helpful for carrying small pieces of hand jewelry for a few moments — like if you plan to propose to your significant other, or if someone else is washing their hands and wants you to hold on to their rings — but that's pretty much it.

For the most part, it's best to ignore them and think about the pockets as a piece of history that's still with us.

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