Chihuahuas, originally descended from the Techichi dog in ancient Mexico, were bred for various purposes including companionship, religious ceremonies, rituals, and even food. While there are controversial claims suggesting their roots in Asia, it is widely accepted that Chihuahuas were developed in Mexico. Today, they are primarily bred as loving companion dogs, but in rural areas of Mexico, they still serve as skilled ratting dogs. Chihuahuas are known for their affectionate and loyal nature, making them popular lap dogs and family pets.