system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do farmers control whether a chicken lays an eating egg or a reproductive egg and how can they tell which kind is laid?
gpt
Chickens lay eggs whether they are fertilized or not, so the easiest way to make commercial eggs is to not allow the males to mix with the females.

But if you need to check an egg you just hold it up to a bright light. You can see enough through the shell to tell if a chick is in there. Commercial operations do this with automated machinery.