Instagram wants to know how old you are... in order to keep people safe they say. 

They say that the changes are being made in the hopes of making the platform safer for younger users and that birth dates, while not visible to the public, will be used to recommend different privacy settings and features. And the new information will also be used to provide more accurate targeted advertising apparently...

"While we expect ads targeted by age to be more accurate on Instagram following this update, this isn't the reason we made these changes," Instagram said in an email. "Our focus is on developing new, age-appropriate experiences for young people using this information."

Reaction to the change was mixed with some thinking it doesn't go far enough because they won't verify the age and people can lie, while others were concerned about giving more information to the social media company.