Thinking it might be boredom as this is my work week, and days are still short so I can't let them out when I get home from work because its dark already so they are in essence, cooped up for a week.
A secure run is really a necessity for anyone who is going to be away from home during the daylight hours.

Hens go broody when you don’t want them to… and won’t go broody when you do. 