I raised two chickens 12 days. Why does a wing grow so slowly? . Are they still growing healthily?

There may be two reasons for the growth rate. First, these two chicks are not laid by the same hen, which is related to genes. Second, these two chicks are male and female, and their growth rates will be different. These pictures seem to be healthy. Usually, we should pay attention to the dry and clean living environment, not high temperature and high humidity, and have a certain activity space. Don't always play with your hands.