Book 31, Question 64
Why are some chicks fluffy and ready to run while others are bald and helpless?
Ducks, chickens, and killdeer hatch with open eyes, a warm layer of down, and legs ready to run.
Robins, woodpeckers, and many songbirds hatch with their eyes closed and almost no feathers. They must stay in the nest for days or weeks while parents feed them. The difference is how long the chick developed inside the egg and how risky it is to stay put.