Chickens are talented escape artists when it comes to finding their way out of your chicken coop and into the outside world. Chickens can be very difficult to catch unless you have spent a significant amount of time taming and socializing your chickens to the point where they will come to you.
Around the Coop
Chickens are social. It is unlikely that a single escaped chicken is going to leave the rest of the chickens behind and head off into the world on its own. There is a good chance that your chicken is still nearby if a single chicken has escaped but the rest of your birds are still in the coop. If your chicken is still hanging around near the coop you may be able to herd her back into the coop thanks to her desire to be a part of the larger group.
Chickens roost in the evening and stay put all night. If your escaped chicken is not coming back to the coop at night then chances are high that she has found somewhere nearby to roost. Chickens prefer to roost off the ground and in the company of other chickens. Check trees, tops of buildings and any other perch that would be high enough off the ground to give the chicken protection from predators.
Ask The Neighbors
Chickens generally won't travel a very long distance away from their companions and their food source. If your chicken or chickens have escaped and you don't see them in the immediate area of the coop then you should check areas within a mile of your home. Ask your neighbors if they have seen your chickens and check any other poultry friendly areas nearby, such as ponds, livestock areas where feed is easily accessible or even the neighbor's chicken coops.
Catching a Chicken
Catching a chicken can be challenging. The easiest way to get a chicken back into a coop is to have multiple people surround her and herd her back into the coop. If that is not an option, you may be able to sneak up on the chicken when she is roosting and catch her by wrapping it in a large fishing net or a large blanket. You can also purchase a live animal trap, place feed in it and hope that your chicken will be hungry enough to go into the trap.