The children may or may not exhibit the trait. It depends if the parents are carriers of the trait or not. If they are both carriers, the children will have a 25% chance of exhibiting the trait, a 50% chance of being carriers, and a 25% chance of not having the allele for the trait at all. If only one parent is a carrier, their children will have a 50% of being a carrier and a 50% chance of not having the allele. If neither parent has the allele for the recessive trait, their children won't either.
