The playground that Ender found was something that was made exclusively for him, to recreate the scene from the Fantasy Game.
I believe that your question may be concerning the following passage from Ender's Game (Chapter 15):
And from the slings that once were used to carry infants along with adults into the fields, he learned that even though the buggers were not much for individuality, they did love their children.
Over here, children doesn't necessarily refer to them as individuals (a parent caring for it's young), but rather as a species (the older caring for the younger).