Because it can be difficult to sex a chicken at birth, having a catch-all genderless term for the baby birds makes sense. It's a little fluid, but generally baby chickens go from being called chicks to being called pullets or cockerels once they grow in feathers rather than down. The saddle or tail feathers on a pullet are rounded, and cockerels have long pointy saddles. A poussin held in the hand In Commonwealth countries, poussin (pronounced / ˈpuːsæn / and less commonly called coquelet) is a butcher's term for a young chicken, less than 28 days old at slaughter and usually weighing 400–450 grams (14–16 oz) but not above 750 grams (26 oz). Broiler: A cockerel of 2 or 3 pounds, at 8 to 12 weeks old. Baby hens are called pullets and are distinguished from baby roosters, which are called cockerels, by the shape of their tail feathers when the chicks are approximately three months old. Hens are highly sociable animals that live in flocks.
An immature female chicken is called a pullet. A mature female chicken is called a hen. A baby chicken is called a chick. Male chickens go from cockerels to roosters once they hit puberty and begin mating; female chickens go from pullets to hens once they hit puberty and begin laying. Cock: A male chicken, also called a rooster.
Chicks cease to be chicks when they lay their first egg somewhere between 16- 28 weeks depending on your breed. Informally, chicks are sometimes also called “peeps.”

Boiler: A chicken 6 to 9 months old. Specifically, Females are called Pullets, and Males are called Cockerels. Cockerel: A young rooster, under 1 year old.

During that time you will be enjoying watching them grow into ungainly ‘teenagers’ then into ‘hen/rooster hood’. Bantam: A diminutive breed of domestic fowl. Terms for Types of Chickens. Baby Chicken is called Chick.They are also called Witty. Baby chickens are most commonly referred to as “chicks.” This is a gender-neutral term that applies to both male and female chickens. Find out more about other chicken breeds. A group of chicks is called a clutch or peep.