The American Pet Association reports that Americans have taken more than 136 million dogs and cats into their homes. While most of the differences between dogs and cats are obvious, Marc Morrone points out some fascinating distinctions. Did you know, for example, that dogs are omnivores and can eat almost anything? They have 42 teeth -- 12 more than a cat -- which allow them to not only consume meat, but plants and grains. Cats, on the other hand, are carnivores and need meat to survive.
In addition, cats are born with 200 million scent receptors in their noses, while dogs have 220 million. Dogs hear at 40,000-cycles-per-second, while cats hear at 80,000; in contrast, humans hear at 20. The tongues of both cats and dogs can taste salty, bitter, and acidic flavors, but only dogs can taste sweetness. Dogs are far more social than cats, instinctively joining packs (if no actual pack exists, you and your family are the closest substitute). Cats don't have the same impulse, accounting for their fierce independence.