Behavior

• Roosters are more vocal than hens.Jupiterimages/Photos.com/Getty Images
  
  The biggest difference in the behavior of roosters and hens is that roosters crow, and hens do not. Chicks may start crowing well before the physical characteristics develop enough to tell the sex of the young. In addition, roosters are aggressive and animated; whereas, the hen is reserved, less active and shy. The rooster also tends to be friendlier with humans than the hen.
  
  

Size

• Roosters are tall and slim, compared to the short squat hen.Jupiterimages/Photos.com/Getty Images
  
  The rooster is taller and slimmer than the hen, which has a more squat, short appearance. The size and strut of a rooster not only determines the dominant male of the flock but also plays an important part during mating. Hens choose the larger males with the most impressive strut and coloring.
  
  

Comb and Wattle

• Roosters and hens differ in the size of their combs and wattles.Jupiterimages/Photos.com/Getty Images
  
  Roosters show off their combs and wattles during courtship, so these features are larger with brighter coloring than those of the hen. A dominant rooster also has a larger comb than other roosters in the flock, and a hen with a larger comb than other hens is usually the dominant hen as well as a better egg producer.
  
  

Feathers

• Roosters show off their long, flowing tails during courtship.Jupiterimages/Photos.com/Getty Images
  
  As with many species, the male develops brilliant colors that are used for attracting females during courtship. The roosters have long flowing tails that they lift and spread while strutting for the female, while the females' tails are much shorter and dull in color. The overall body colors of the rooster are brilliant and vibrant compared to the hen, which tends to have dull, pale-colored plumage. A hen and rooster differ in the size and shape of their neck feathers as well. The rooster has thin neck feathers with pointed tips, and the hen's are rounded and wider.
  
  

Feet

• Not only are a rooster's feet larger than a hen's, but roosters also have a spur located on the insides of their legs that is missing from the legs of a hen. This spur is a bony cone-like projection that continually grows, much like the human toenail. Roosters use this spur as a weapon during a fight. Many breeders of domestic chickens have these spurs removed to protect the flock and themselves from getting hurt.