Black Polish bantam chickens come in a couple of different varieties. Although the body of a black Polish bantam is always black, some of the birds have a white crest of feathers on top of their heads. These birds are called white-crested black Polish bantams. Other birds are crested in black, or may even have a black beard of feathers under the chin. Birds with beards are called, for obvious reasons, bearded black Polish bantams. However, in whichever variety you have, there are several ways you can tell a rooster from a hen.
Observe the chickens as they grow. Female chickens usually grow adult wing and tail feathers before the males do. Chickens that are maturing quickly are likely hens.
Look for red combs on the chickens. Combs usually start to grow when the chickens are about five weeks old. These brightly coloured pieces of flesh are located on the chicken's face. A red comb indicates that the chicken is a rooster, as only male chickens grow red combs. Hens grow much smaller combs that are yellow in colour.
Look at the shape of the feathers on the chickens. A rooster's feathers are quite pointed, while a hen's feathers are more rounded in shape.
Look at the back of the necks of the chickens. At about three months of age, male chickens begin to grow long, pointed feathers there, which look slightly different from the feathers surrounding them. These feathers are called hackle feathers.
Observe the shape of the chickens' heads. Female chickens have small, rounded heads, while male chickens have slightly larger heads. A rooster's head is also sharper and more angular in appearance.
Look at the chicken's legs. Fully grown roosters have slightly longer legs than fully grown hens do.
Look near what would be the ankle of the chicken. Roosters grow sharp clawlike points, called spurs, here. Hens do not grow these spurs.
Observe the crests of the chickens. Fully grown hens have fluffy, rounded crests, while a rooster's crest should look somewhat spiky.
Weigh the chickens. Roosters almost always weigh more than hens. Roosters should weigh about six pounds when they are fully grown, while hens should weigh about 4 1/2. Roosters also gain weight faster than hens while they are growing.
Listen to the chickens. Roosters do a lot of crowing, which is an extremely loud noise, while hens never crow. If you hear a chicken making a loud crowing sound, you know it is a rooster.