i had a runt this hatch, too. Not really micro-sized, but much smaller in comparison to her hatchmates. She has been picked on mercilessly by my dominant male duck (pulled all her feathers out of her head trying to breed with her) so i finally had to move her into her own private duck condo
. She hates the separation, but her feathers are finally starting to grow back. So my advice is to just watch her/him and see how the other ducks treat her/him.
