What are they thinking?
If you've always suspected that animals are smarter than they get credit for, that there's more going on behind those eyes than a desire for food or attention ... you're not alone.
In some species, especially elephants, great apes and marine mammals, the old phrase "dumb animal" borders on heresy.
In fact, the line between human and animal intelligence is fading fast.
"I think it is fair to say that literally, monthly, there are fairly major discoveries about things that we long thought were unique to humans, now look like some of the building blocks are in place in other animals," said Harvard professor Marc Hauser.
Take capuchin monkeys: they're not the brightest lights in the animal kingdom, but behind all that cuteness is the mind of a master problem-solver. Dave Peranteau works with capuchins for Six Flags in New Jersey.
He says they surprise him every day.
"And even on days off, the staff will call and say, 'You'll never guess what Jester did today," he told Smith.
For instance, Jester, a four-year-old male, taught himself to pick locks well enough to bust out of his cage.
"Not only did he let himself out," said Peranteau, "but he wanted to have party, so he went around and let all of the other animals in the area out - birds, snakes, coatis, you know, you name it. Everything was out."
But recent studies at Emory University have shown that capuchins also have the mental capacity to understand concepts like fairness, and sharing with their fellow monkeys.
"For the most part I do believe that they do have some sort of feelings," Peranteau said.
"I think many animals are more intelligent than we generally think," said Emory's Frans de Waal.
De Waal has pondered animal intelligence for decades, including a 2006 study that broke new ground about how animals see themselves … literally.
Most animals - and human children under two years old - see their mirror image as another creature: they don't realize that it's really their own reflection. But elephants do.
De Waal's team discovered this with a giant mirror at the Bronx Zoo.
"The elephant had a big mark above its eye and walked up to the mirror and started touching it," de Waal said, "so the elephant has that kind of self-awareness that you find in children over two."
It turns out that elephants have an advanced sense of self, which means (in part) that they're smart enough to be capable of really caring about others. The only other creatures thought to have this ability include apes ... and human beings.
Also, there are marine mammals like dolphins.
We all know that dolphins can be trained to do a lot of things, but are they tricks or something more?
Between shows at Six Flags, trainers lead an exercise that keeps the ultra-smart animals from getting bored.
It's called an "innovate session": the dolphins can do whatever they want, as long as they don't repeat the same behavior.
"So, they understand the concept of 'different'?" asked Smith
"Yes, they do," said Jessica Parenteau, who helps shape their behavior by blowing a whistle when they do something different. "And they'll wait to hear this whistle, [which tells them] 'That's it, that's exactly what we're looking for.' So, each time they do something new and creative, we blow that whistle."
"'That's a good boy'" said Smith.
"Yeah. And that shapes their creativity, because they're like, 'Well, I'm gonna try this then. And I'm gonna try this and see if I can get a whistle with this."
"That's incredibly smart," said de Waal. "Dolphins are known to be smart but to understand that you need to do something new each time and to innovate a new item that you're going to do, that's incredibly smart."
Many pet owners say that the most intelligent animal they know is their dog, and they do understand what we say ... at least some of the time, depending upon the tone of the voice
"If I say to my dog, 'What a wonderful dog you are,' the dog'll be very happy," said Hauser. "If I say, 'What a stupid little dog you are,' they'll also be very happy. It's the tone in my voice. It's the music that they're paying attention to, primarily. But even there, we want to be cautious, because some studies have now begun to show that dogs, for example, may actually understand that words pick out certain kinds of objects in the world. So, if I say 'Apple,' I mean that red, shiny thing that I eat, not the chair."
The difference - and what separates us from other animals - is the human ability to communicate complex thoughts with one another. But animals do seem to understand emotion.
"Are animals attached to us? Absolutely," Hauser said. "When you leave your pet behind, you see signs of depression. Is it like our depression? Well, I don't know if it's like our depression. I don't even know what your depression would be like, relative to my depression. But do animals feel strong bonds? Undoubtedly, yes."
"Can we call that love?" Smith asked.
"Why not?" Hauser said.
Of course, the question of whether the capacity for love makes animals more intelligent is probably best left to the individual ... of whatever species.