In one week Chicks triple in size and grow enough feathers to fly short distances. I CAN NOT BELIEVE how fast my chicks are growing. One of the Amaraucna chicks had pin feathers 3 days after hatching and now one week later almost fully feathered wings and tail and can already fly 8 to 10 inches off the ground. I had to put a cover on the brooder last night. I'm stunned at the growth rate.