Question: why do chickens lay eggs

Adam Hargreaves answered on 23 Jun 2017:

Hi Jack,
That’s because unlike the Eutherian mammals (a group of mammals that contains us humans, elephants, rodents etc.) chickens don’t have a uterus (womb), so their babies don’t develop inside the mother. Instead they lay eggs which are designed to protect the embryo, stop it from drying out, and to contain enough yolk which is the embryos source of nutrients for it to grow. In a lot of ways it’s a good strategy, it means the mother can lay her eggs and then get on with foraging for food, without carrying all that extra weight around. However, it also means that the eggs can be left vulnerable, especially because a lot of predators see them as a source of food.