Dogs use non-verbal communication just like humans do, relying on familiar cues to express themselves.
Unfortunately, though, these similar non-verbal communications have a completely different meaning when a dog performs them vs. a human, which can lead to many misunderstandings between a dog and their handler.
Yawning
With humans, a yawn can signal that you're tired or bored. However, when a dog yawns, it means they are uneasy or tense; the yawn is an attempt to ease both themselves and their owner.
Lip-Licking
A human may lick their lips when they are feeling hungry, or when their lips are feeling dry. However, if a dog licks, it is a sign they are uncomfortable or even anxious. Licking causes them to calm down, so when your dog is feeling upset, they may try to lick you in order to relax.
