Instagram notifications?

Hi, I've looked for this answer online and can't find it. I have an iPhone 5, iOS 7. I am trying to make it so that when I get Instagram notifications, the little red number appears on the Instagram icon on the home screen. I've played with the settings in the Instagram app itself and in my general notification settings on the phone, but can't seem to figure it out. The only options I have are to have a push notification appear or an alert box. There simply may not be a way to do it, but if anyone knows I would appreciate it. Thank you