When a dog is feeling fearful or anxious, they may put their ears back as a way to protect themselves.
When a dog is feeling submissive, they may put their ears back as a way to show respect.
When a dog is concentrating on something, they may put their ears back to help them focus.
When a dog is listening to something, they may put their ears back to help them hear better.
Dogs can also use their ears to communicate with each other. For example, a dog may put their ears back to show aggression or dominance.
If a dog is in pain, they may put their ears back as a way to protect their ears from further injury.
In some cases, a dog may put their ears back due to a health problem, such as ear infection or ear hematoma.