Dogs are very expressive animals. They communicate when they’re feeling happy, sad, nervous, fearful and angry, and they use their ears to convey much of this information. 

When your dog is relaxed and comfortable, he’ll hold his ears naturally. When he’s alert, he’ll raise them higher on his head and he’ll direct them toward whatever’s holding his interest. Your dog will also raise his ears up and forward when he’s feeling aggressive. If your dog has his ears pulled back slightly, he’s signaling his intention to be friendly. If his ears are completely flattened or stuck out to the sides of his head, he’s signaling that he’s frightened or feeling submissive.