Today the dogs were in the back yard, and I was outside with them, throwing balls. I looked up to the sky, saw a hawk circling, and said, "Oh, look, guys, there's a bird up there."
Hero looked up (whether he vaguely understood my words or followed the direction of my gaze, I don't know) and immediately went into Guard Dog Mode. He began barking ferociously, and bounded into action, racing back and forth across the yard as the hawk circled overhead. He even leapt upward a couple of times, though the hawk was far overhead and he wasn't going to catch it unless he suddenly sprouted wings. He kept it up, barking and zooming back and forth, till the hawk flew off, then strutted back to me, pleased with himself and his guarding abilities.
All the while, Impy stood by my side and watched with what looked very like canine amusement: I love my brother, but man, is he dumb.