My 2.5 weeks old chicks are in guinea pig cage brooder. They have food, water and grit. They have enough space to roam around and temp is comfortable range. When they find me around (brooder is covered with cardboard, they can't see me), they start peeping so loud. Start gathering front of the door. When I open the door, they just jump on me and stay for while and go back to brooder. Jump on/off me and fine, soft peeps going on. But once I close the door, they start peeping loud and jump on the door and trying to get out. Are they bored in the brooder, that's why they do that?? How do I entertain them without me??