Polk Central ElementaryPhotos: Polk Central fifth graders hatch eggs Polk Central Elementary fourth graders recently hatched eggs as part of their animal studies unit. Published April 16, 2023 Flipboard Reddit Pinterest Whatsapp Whatsapp Email Polk Central Elementary fourth graders recently hatched eggs as part of their animal studies unit.Students can now observe the adaptations the chicks have to allow them to survive as well as study their needs. In this article: