Facebook’s monthly user base of kids between 12 and 17 will fall 3.4 percent compared to last year, according to eMarketer. The social media site saw a decline of 1.2 percent among the same group last year when compared to 2015. Instagram is expected to see the number of 12 to 17-year-olds grow 8.8 percent this year. Snapchat is expected to grow to have more users in the age group than either Facebook or Instagram.