My young Columbian Rock (about 18 weeks) is acting off. She follows the other 2 girls into the run but seems to doze more than eat, scratch, or drink. When I let them out to have free run of the yard, she went happily, pecked at a few leaves and bugs but continues to just scrunch down and doze more than the other 2. She's my youngest girl...no real comb and just starting to look more like a hen than a pigeon...is it possible she's just experiencing chicken growing pains??