Pets: Are they who we think they are?

CHICAGO, Feb. 9 (UPI) -- My dog put her bone in the refrigerator. No kidding!

I was standing in front of the fridge Saturday surveying leftovers when my year-old puppy popped her head inside and left her rawhide bow tie bone on the bottom shelf.

A cute coincidence I thought. Dogs can't be that smart and frankly it isn't unusual for a dog, or cat for that matter, to poke its head inside a refrigerator.

But the incident made me wonder, "Just how smart are these critters?"

Even undomesticated animals show incredible intelligence. Colonies of monk parakeets (Quaker Parrot) set up residence in Chicago's Hyde Park in 1973 and have managed to thrive despite the frigid Midwest winters. And crows, whose local population was decimated by the West Nile virus, have returned -- sometimes with hundreds noisily roosting in trees.

My wife insists their cacophonous, cawing and cackling may be a "crow convention" to elect an alpha bird to lead the flock. With a lifespan of up to 20 years, crows are among the most intelligent birds on Earth: They can use twigs as tools and pick out faces in a crowd.

As for the mystery of migration, how the heck do birds, fish, animals, and moths and Monarch butterflies know when and where to go?

MRI scans performed by Emory University dolphin expert Lori Marino have shown the neocortex in the brain of a dolphin is more developed than in humans and structured to allow for self-awareness and "complex emotions."

Dolphin brains are about "five times larger for their body size when compared to another animal of similar size," Marino told Discovery News. "In humans, the measure is seven times larger -- not a huge difference."

Joining dolphins in the intelligence pecking order are chimpanzees and orangutans, elephants, parrots, crows and dogs.

When a dog tries to urinate on seemingly every tree, bush and fence during a walk outside, is it marking territory or is it leaving a scent equivalent of a text message for other dogs? We may never know.

No story gets a bigger response than an animal saving a human by warning of danger or sacrificing its life to save its family.

Last month, fire officials in Wonder Lake, Ill., credited a pet cat with saving the lives of a sleeping man and a woman pregnant with twins.

"The cat started bugging him and when he awoke he noticed that the living room was filling with smoke," Wonder Lake Fire Protection District Assistant Chief Mike Weber told the Chicago Sun-Times. "They were lucky."

I've seen scores of similar stories involving cats, dogs, birds and even a pet pot-bellied pig.

My dogs have never taken heroic action, but like most pet owners I know, I think they're smart.

The oldest, a 7-year-old wire fox terrier, knows the names of more than 50 toys, which he fetches on command.

We can't say PetSmart without him going ballistic so we've invented "dog Latin" and call his favorite place, "etpay."

Some dogs have been documented with a vocabulary of hundreds of words, though canines rely more on scent than hearing or sight.

Your pets might not know the meaning of every word you say (thank goodness) but it's unbelievable how correctly they respond.

When he was a pup, my wife would come home for lunch and spend time working on puppy class assignments with him. She quickly noticed the little terrier would sit in front of her as she talked tilting his head from side to side as he tried to figure out what she wanted.

Early on, we struck an interspecies pact that when he had to "go" I would take him outside if he told me first. Sometimes he would run to the door and bark, other times he would paw me repeatedly and sometimes he would just stare unmovingly. Anyone with a terrier knows what I'm talking about. Do we own our pets or do they own us?

Barkley quickly gained the reputation as "the most walked dog in the neighborhood." But over the years he's seemed to understand that I meant he should not take advantage of the deal, and that if I take him out he had better be prepared to "do his business."

We can't remember the last time he had an "accident" in the house. Maybe he's just well trained, but maybe he also understands.

In Plymouth, England, Casper, a rescue cat famous for riding the same bus daily for four years was killed while crossing a road to catch the bus.

Susan Finden, his owner, told The Daily Mail she named the cat Casper because it would vanish like a ghost.

"But then some of the drivers told me he had been catching the bus. I couldn't believe it at first, but it explained a lot," she said. "He loved people and we have a bus stop right outside our house so that must be how he got started. He'd queue up in line good as gold -- it'd be 'person, person, person, cat, person, person.' He had no road sense whatsoever but he loved people."

In Moscow, a Russian-language Web site, ran photos of stray dogs that have learned to ride the Metro.

They sleep in commuter stations, curl up on the floor or an empty seat, beg for food and more surprisingly rarely relieve themselves on the trains. Moscow has an estimated 35,000 stray dogs.

Animal experts surmise the dogs have changed their social structure to fit living in the city, rewarding the smartest dog instead of the most aggressive, with alpha male status, stuff.co.nz said.

Some dogs have even learned to wait for a "walk" signal to cross a street.

Animals supposedly live in the moment, and even though my puppy put her bone in the fridge it doesn't mean that she did it because that's where the good food is kept.

After all, this is the same pup we nicknamed "Chewy" after she gnawed the legs of our kitchen chairs and piddled on the floor when she was caught in the act.