Sounds human to me too. I would ask neighbors if they saw suspicious vehicles around....bored teenagers with too much time on their hands this summer? IDK. Sometimes these people get careless and leave sign or get to talking too much. I would put out some feelers. Ugh...to lose all those pullets. I can't imagine.
Sorry Cyrus.
Hens go broody when you don’t want them to… and won’t go broody when you do. 
