I recently asked a 5-year old why she liked cats. "They are cute," she replied. "But I like dogs, too. They are smart," she added. I nodded, thinking to myself that that was a smart answer.

Dogs carry out amazing tasks. When I went to live in Australia in 2007, I had my first encounter with a food detector dog. On the plane they had us fill out various forms with explicit warnings against importing food and drugs. As I was traveling with my daughter, who was three at the time, I had bags full of apple sauce, cheerios and raisins. I carefully disposed of these items prior to entering the line for immigration. As I was standing in line with my daughter in a stroller, a police dog dragged a police officer closer and closer to the stroller. The dog started sniffing.

"Are you importing any food?" The police officer asked.

"No, Officer, I got rid of everything," I replied in compliance.

The dog kept sniffing the hand luggage hanging from the stroller's handles. It finally settled on one particular bag.

"Would you please open your bag?" The police officer sent me a mean look.

I placed the bag on the floor and opened it. The dog dove his head into the bag and a few minutes later he presented a tiny ziplog bag with an old banana peel to the police officer. I got off with a warning.

We don't use cats as food detectors. We don't use them for very many purposes. Dogs get their paws dirty. They serve as police dogs, military dogs, drug detector dogs, fire dogs, seeing-eye dogs, dogs, and cancer detector dogs.

A U.S. Navy dog was a member of the SEAL Team Six, the elite military operatives that killed Osama bin Laden. Military dogs are trained to jump out of airplanes and helicopters, and they are better bomb detectors than the fanciest bomb detection technology today. Even elephants, mules, dolphins and sea lions have served in the military. But police cats, military cats and seeing-eye cats are rare.

But cats certainly aren't dumb. Their brains may be small compared to ours, occupying only about 0.9 percent of their body mass compared to about 2 percent in an average human and about 1.2 percent in an average dog. But size doesn't always matter. Neanderthals, the hominids that went extinct more than 20,000 years ago, had bigger brains than Homo sapiens, but they probably weren't smarter than the Homo sapiens that beat them in the survival game.

Surface folding and brain structure matter more than brain size. Unlike the brains of dogs, the brains of cats have an amazing surface folding and a structure that is about 90 percent similar to ours. The cerebral cortex of cats is greater and more complex compared to that of dogs. The cerebral cortex is the part of the brain responsible for cognitive information processing. A cat's cerebral cortex contains about twice as many neurons as that of dogs. Cats have 300 million neurons, whereas dogs have about 160 million. In fact, cats have more nerve cells in the visual areas of their brain, a part of cerebral cortex, than humans and most other mammals.

Like brain size, number of neurons in the cerebral cortex may not be a good indicator of . But it's a better indicator than brain size. The cerebral cortex is the seat of rational and complex problem solving. It also interprets inputs from the senses and from emotional processing that occurs subcortically. It is involved in the planning of action, the interpretation of language (or other forms of communication), and it is responsible for the storage of short-term and . Cats have longer-lasting memories than dogs, especially when they learn by doing rather than seeing.

If cats are so smart, why don't we use them as police cats, military cats and seeing-eye cats? Maybe because they are too smart to be enslaved by humans. As Huffington Post puts it, "dogs come when they're called; cats take a message and get back to you." Dogs have been domesticated for thousands of years to excel at social tasks, whereas cats have not. There is a reason for that: Cats are more impulsive than dogs and have far less patience. They don't easily tolerate frustrating situations for long periods of time. If an activity isn't obviously rewarding to them, they would rather do something else. Dogs will do almost anything for a treat or a smile on their owner's face. Dogs clearly have a higher social IQ than cats but cats can solve harder cognitive problems, if indeed they feel like it.