I have a little sidewinder neonate (Crotalus cerastes) that in the 2 months I've owned him, has never ever once flicked out his tongue to smell. I've had to assist with feeding him pinkie heads before, and noticed that I didn't see the black tip of a tongue in his mouth either. Makes it difficult to try different scents on his food when he never smells it! haha. I'm starting to suspect it may have been a birth defect? Was just curious if anyone else has ever had a similar situation.