I have 1 black sex-link, 2 easter chickens, and 1 Rhode Island Red. They are all 23 weeks and 3 days. They are all laying eggs except for the Rhode Island. We are getting 3 eggs a day. The Rhode Island is going into the nesting box and sitting in there for about 30 minutes then leaves the box without laying any eggs. What does this mean? Is she possibley getting ready to lay?