Chicken Life Cycle Activities and Crafts | KidsSoup Chicken Life Cycle Activities and Crafts. A hen lays an average of 300 eggs per year. When a hen is "broody," it means she wants to hatch her eggs. The hen will sit on her eggs to keep them warm so that they will hatch into chicks. A fertilized egg starts developing into a chicken when its temperature reaches 86 degrees fahrenheit. A chicken takes 21 days to hatch. The life cycle of a chicken worksheet – Preschoolplanet The life cycle of a chicken worksheet for preschool. Everybody borns and dies. Animals and insects also a have life of cycle. Today we have chicken on our worksheet.