Dogs look at our eyes. Dogs make eye contact and look to people for information. They study us to figure out where the food is, what we are feeling, and what is happening.

In one study, the dogs made 1,272 attempts to detect which patients had cancer—and missed only fourteen times. In another experiment, they sniffed out the cancer every time.

if you want your dog to sit, try using a lower-pitched command that drops near the end. This is a tone that might be more likely to help a dog relax.

One scientist coined a word for it: umwelt, or “self-world.” (You say it OOM-velt.)

they have inherited something important from their wolflike ancestors—an interest in being around others and in paying attention to what those others are doing.

For dogs, smell tells time.

So a dog living with humans is not living in a pack. But he is living in a family. Like other families, people and dogs share habits, preferences, home. We sleep together and rise together. We walk the same routes and even stop to greet the same dogs. Our dog-and-human family works because we share basic rules of behavior.

The tongue isn’t the only path for chemicals like pheromones to get to this organ. A nice moist nose works too: This is one reason dogs have wet noses.

They are nearly as good as we are at noticing changes in pitch.