There are 2 types of people in this world, those who enjoy drinking milk and those who don’t. It really doesn’t matter which side of the fence you fall on, however, you will recognize the milk jug handle and the colorful label from the moment that you see it. There is also something else associated with a gallon of milk that is important. It’s an inverted circle found on one side of the container.

More than likely, anyone who drinks milk on a regular basis has noticed the inverted circle. Although you may see it, you may not really think about why it is there. Actually, it serves an incredibly useful purpose: it keeps the jug from blowing up.

Distractify reports that the circle on the milk jug side gives structural integrity in case you drop it accidentally. Perhaps you have had the unfortunate experience of dropping a gallon of milk before but, thanks to the little circle, the mess was averted. If the jug hits the ground or any other surface, the circle expands to keep the milk on the inside of the plastic.

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Along with keeping the jug from blowing up if you drop it, it also keeps it from popping in the refrigerator.

If you leave milk in your refrigerator too long, it is going to build up gas. That is why milk smells sour when it is expired. As the pressure builds from the gas, the circle will expand to provide additional space on the inside of the plastic container. That inverted circle will also keep the milk jug from exploding if you decide to put the milk in the freezer.

It’s always a good idea to pay attention to the world around you. Even little things, such as that inverted circle on the side of a milk jug, serve a useful purpose!