I have 3 chicks in the brooder. They have all been doing fine but today I noticed that one, Eli, is letting her wings droop down, not picking them back up. She is also not drinking unless I carry her to the water and dip her beak in. She can still walk but tends to stand off to the side and is not as active as the others. She's eaten at some point (I didn't see her do it but her crop feels slightly full) and ideas on what it could be or suggestions on what I should do?