Chihuahuas have an alert, active, and often playful nature. They can be quite intelligent and learn well with reward-based training techniques. The Chihuahua's small size lends itself well to living in areas with limited space such as apartments. While its size also attracts children to the Chihuahua, as with all dogs, extremely close supervision is needed to prevent accidental injury to the dog and its subsequently developing fear-based defensive aggression.
The Chihuahua is one of the most ancient of dog breeds, with its origins dating back to the Mayan civilization. The breed is believed to have descended from the ancient Techichi, a dog that played an important role in both the Toltec and Aztec cultures. Some believe that the Chihuahua is a result of the crossing of the Techichi and the Chinese Crested, which came to South America from Alaska. Due to the destruction of the ancient civilizations, the breed faced extinction. However, remnants of the breed survived in Mexico and the Chihuahua was introduced to the United States in 1898. The Chihuahua was recognized as an official breed in 1904 by the American Kennel Club and by 1915, thirty Chihuahuas were registered in the States with that number jumping to over 25,000 by the early seventies.