I’m a teen living in New York, Mashable reports. All of my friends have social networks — Instagram, Vine, Snapchat, etc. Facebook used to be all I could talk about when I was younger. “Mom, I want a Facebook!” and other whining only a mother could put up with. But now, at 13, I’ve been noticing something different. Facebook is losing teens lately, and I think I know why. Part of the reason Facebook is losing my generation’s attention is the fact that there are other networks now. When I was 10, I wasn’t old enough to have a Facebook. But a magical thing called Instagram had just come out … and our parents had no idea there was an age limit. Rapidly, all my friends got Instagrams…