Calming signals
Small, easily missed gestures — lip licks, head turns, a slow blink, a yawn — that animals use to defuse tension rather than because they are tired.
The term was popularised by the Norwegian trainer Turid Rugaas for the behaviours dogs offer when they want a situation to cool down. A yawn in a waiting room, a sudden interest in sniffing the ground, a head turned away from an approaching dog: none of these are boredom, and all of them are communication.
The reason to learn them is that they come long before a growl. A photograph of a child hugging a dog that is licking its lips and showing the whites of its eyes is a photograph of a dog asking for help, and reading it correctly is how bites get prevented rather than explained afterwards.