Why Your Dog's Tongue Might Be Their Most Important Body Part Kinship How to turn off email sounds on the iPhone 6, 6S, or 6S Plus Dogs will flick their tongue as an appeasement signal but also as a signal they're relaxing. While similar each signal has subtle differences. I will do posts on both. The tongue flick How Dogs Really Drink: The Physics of a Flicking Tongue by Dianth Xue Medium