2 chicks shaking heads a little bit

[mohsin]

2 of them are shaking their heads a bit. What can i give them? Eggs? Or apple cider vinegar?

 

[lazy gardener]

2 of them are shaking their heads a bit. What can i give them? Eggs? Or apple cider vinegar?

Does it seem to be a lack of control? How old are they? What are they on for feed? How many chicks all together? When did it start? Is it getting worse?