Why does snake stick out his tongue all the time?

Last week when I was helping Ritvik wash his hand, after he came back from school I spotted a star on his hand. (Teachers give a star to kids to encourage and appreciate them). I asked him why did teacher give him a star today. He said because he answered the question correctly. And what was the question ... I asked. He said "Why does snake stick his tongue out, all the time?, I answered - to smell". I said "But doesn't he smell by nose". He said, "Know Mommy, don't you know, we smell by nose but snake smells by his tongue". I did not contest it and checked it on Internet, he was right. Snake does smell by his knows. I went back to him to ask how did he know. He told me Carla told him. Carla is a Zebra in Mama Mirabella from Ceebeebiees. I felt proud of him but sorry that I did not know it. Got to keep pace with the kid.