My newly hatched Mallard duckling cant stop its feet from shaking, it look like theyre vibrating! It also seems to not be able to walk properly and falls onto its back alot. It was hatched with the yolk not fully absorbed aswell as ruptured, and a small bit of tissue hanging from the umbilical area aswell. The yolk and tissue problem is now fixed but could it be related to the shaking? the duckling is very active and vocal otherwise, However it does keep one eye closed majority of the time.