<human>:  What are the differences between a pug and a Chihuahua?
<bot>: The main difference between a pug and a Chihuahua is their size. The pug is typically 10-13 inches in height and 14-18 lbs in weight, while the Chihuahua is usually 6-10 inches in height and 3-6 lbs in weight. Pugs have a broad, square-shaped head and a scrunched muzzle, while Chihuahuas have a triangle-shaped head with a pointy muzzle. Pugs usually have a smooth, short-haired coat, while Chihuahuas can have short, long, or wiry-haired coats. Pugs also tend to be more social and friendly, while Chihuahuas can be wary of strangers and more prone to barking.