It might have gone unnoticed by some. According to a recent social media post that received hundreds of responses, “Most people will go their whole lives

without ever knowing what the circular indent on the side of the milk jug is for.” According to one Facebook user, Cory Anderson, “the milk is going bad when

it pops out.” According to a different social media user, the indent may be related to the carton’s capacity to expand in cold weather. According to Andrew

Serpico, a Facebook user, “the bubble gives the milk somewhere to expand to so it won’t bust the carton if you freeze it.” The indent, also known as a mold,

is more than just a fashion choice, according to The Dairy Alliance, a group that advocates for dairy products and information about the dairy industry.

It makes the container sturdy enough to hold the milk inside and aids in regulating how much milk is put into the jug. Furthermore, spoiled milk has nothing

to do with the indent. According to the Dairy Alliance, “the indent wouldn’t pop out because the milk’s age is just a

little too old, even though such an invention would be helpful in a world of confusing dates on food packaging