Try this experiment the next time there is a baby in front of you in church.
When you catch the baby's eye, stick out your tongue. The baby will stick out his or hers most of the time, regardless of how little they are.
One time I was sitting in a women's meeting with this cute little tiny girl in front of me. She stuck out her tongue and we sat with our tongues out for the longest time. Then we lost track of each other for awhile. When we again locked eyes, she immediately grabbed her little juicy tongue with her hand. She remembered me. I was the tongue lady.
It's amazing that babies, even really young ones, will stick out their tongues. Babies know they have tongues.