A pair of chickens is simply called a pair of chickens. They could also be called a mated pair (if they are that), a small flock, or even a couple. Or, be creative and make up a name that is descriptive and unique to that one pair of chickens.
Slick chick.
kickin' chicken
In the film, Chicken Run, the chicken that knits is called Babs.
A set ordered pair is...called a set ordered pair
hen penhen pen
Thick chick.
a mother chicken is called a hen.
A pair of pheasants is called a brace.
A chicken.
A baby chicken is called a chick.
I believe it's hen pen
A pair of inequalities joined by "and" is called a conjunction, while a pair of inequalities joined by "or" is called a disjunction.