Smell is a primary sense for dogs. It's the way they socialize. It's the way they navigate. It's the way they explore.

That's Ed Young. He's an author and Pulitzer Prize-winning journalist at The Atlantic. He also just published a book called An immense World,

How Animal Senses Reveal the Hidden Realms Around Us. And as he was writing the book, Ed became a dog dad.

So his name is typo, he's a corgi. We got typo after I'd written about dogs and smell in this book and it has profoundly influenced the way we've raised him.

Dogs have an incredibly sensitive sense of smell. Some have been trained to smell bombs and drugs, even cancer, even COVID.

And for dogs, going for a walk isn't just a chance to do their business and get in their doggy steps. It's also an exciting smell adventure. One that Ed and his dog typo go on every day.

We go on what we call a sniff walk, like we go at his pace and we do what he wants. And what he wants to do is sniff. Like he will spend 10 minutes exploring a bush.

You know, he will take half an hour to just go around the block because he's exploring the world with his nose. And I find it kind of wonderful. Like watching him take the utmost care, like sniffing every leaf on a plant.

For dogs, it's also a way of connecting with other dogs.

I had this moment when I was looking at Instagram my phone and watching typo sniff a patch of pee that some other dog had left a few hours early and thinking,

that this is the same activity. This is a deeply social act. And it's an act of like keeping in touch with what friends of ours have been up to even though they're not directly in our presence.

We all know about the five human senses, sight, smell, hearing, touch and taste. They literally help us make sense of the world.

We need them to move around to find food and shelter and to communicate and connect with each other. Animals of course have senses too, including a bunch that we don't have.

So to kick off the new season of chasing life, I sat down with Ed to give you a bird's eye view, pun intended, of the realm of the senses and the animal kingdom.

Did you know that scallops can have as many as 200 eyes? Until I read Ed's book, I didn't even know that they could see.

I also didn't know that seed turtles used the Earth's magnetic field to allow them to swim around the world and then still find the exact beach where they were hatched.

Learning about these animal senses made me feel like a kid again, full of wide eyed wonder at nature's beauty and creativity.

It also gave me a richer sense of the world and a better understanding of our place in it. I really hope it does the same for you.

I'm Dr. Sanjay Gupta, CNN's Chief Medical Correspondent. It's time to start chasing life.

So the senses are about taking the causing chaos of the world and making meaning out of them.

They take in all the fairly abstract stimuli around us, like waves of pressure that we call sound, like electromagnetic radiation that we call light, and through some chemical wiseries turns that into neural signals that give us the experience of a sunset or smell of a cup of coffee or the sound of bird singing.

It's really incredible to realize that our bodies can even pick up on these external stimuli and then convert those into experiences.

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