What does is mean when someone says there chicken is perching or learning how to perch?
Well a perch is a place for your chickens to roost, either by sitting or resting.

The roosting perch is the place where the bird will be all night long with his or her flock mates. They will be snuggling up to one another on long winter nights.
The main difference between a roosting perch and a regular perch is just the amount of time your birds will spend on that specific perch.
The regular perch is where they will sit, have a nice nap, watch other chickens and to keep out of the way of everyone else. You may notice that if your flock is roaming around

WHAT TO KNOW:

Roosting perches should around 1.5 to 3 feet high, depending on your flocks age. If you have older birds then you could put smaller perches, so they do not have to jump down as far. There are such things as arthritic hens!
Unlike the older birds, the smaller ones take pleasure in higher roosts. The higher the perches, the more the chickens will enjoy flying up and jumping down. If you set the perches around 4 to 5 feet high and your chickens are using them, it should be fine. But you have to keep in consideration that leg and foot injuries could happen if they are trying to jump from a high angle.

Each hen should have around 9 inches of space on the perch. Even though you’ll find your birds all snuggled up in the winter time for warmth, in the summer, they like to be spread out to be able to get cooler air on their bodies. It is highly recommended that your roosts should be higher than where your nesting boxes are. Some hens might choose the nesting boxes over the perches and it might create more of an issue for you since you are the one going to have to mock out the boxes.