(FOX40.COM) — Just about every plastic milk jug has a circular indent placed on its side, but why? Is it just decoration? Does it help determine if the dairy product is expired? Some people may ...

(KTXL) – Just about every plastic milk jug has a circular indent on its side, but why? Is it just decoration? Does it help determine expiration? Some people may not have ever noticed it.

During the summer, plastic shrinks because of heat so the indents are made slightly larger to prevent milk overflow, according to Food Republic, a news outlet for recipes and cooking tips.