During the second half of the school age stage, the child normally forms strong relationships with his own sex and age group; this is the so - called gang stage. (religion-online.org)
Yet, don't worry since the manufacturers will mark on the label what size of nipple suits with a specific age stage. (shrewdmommy.com)
Did you know dogs go through a teen - age stage just like human kids do? (petliferadio.com)