I had the same problem determining whether pictures of shiny packaging around smooth soap was sharp one time! It’s funny how that works sometimes!
I would say that the eyes (which aren’t fuzzy, and thus easier to tell if they are in focus or not) do not appear to be in focus on the first and second one.
I love the creative “poses” and different locations! Well done. My favorites are the chick in the hands and the chick on top of the pail. The bill open on the pail one really adds some personality. The highlight in the eye of the chicken in the hands one really makes that one feel alive and “deep”. Perhaps using flash at a SUPER low power (just enough to add a catch light) would help the other shots.
Perhaps in post I would try to bring out the yellow color in the feathers (without it looking over-saturated, of course).
I think the 4th one would be worth submitting for Lightstock.