If you want to mix them in with the older hens, have the chicks in a little chicken tractor(or separate pen)just outside the older flocks run, when they are old enough to be outside. You can put your chicks outside when they are about 3 or 4 weeks old, but they still might need a heat lamp.
Inhalation is the process of bringing air into the lungs while exhalation is the process of pushing the air out of the lungs. Inhalation helps the body bring in oxygen and exhalation helps the body expel carbon dioxide. Continue Reading.
The increased volume of the thoracic cavity causes air to rush into the lungs. Exhalation occurs when the diaphragm and rib muscles relax, reducing the volume of the thoracic cavity. The expansion and contraction of the thoracic cavity occurs between 12 and 20 times each minute in adults.