This study aims to explore the meanings communicated by young children with visual cultural semiotic resources available in the science classroom. It is a case study in an Early Childhood Education classroom of 23 children (3-4 years old) and their teacher, all engaged in a long-term science project about snails. We focus on the analysis of two series of drawings of snails made by children a month apart, examined through two complementary lenses: comparative content and social semiotics. The findings show that, during their first year of formal schooling, children acquired a range of semiotic resources to communicate to others, which are part of their classroom culture, rather than explicitly taught. Children used these resources to construct sophisticated meanings through their science drawings, highlighting what they considered important and accounting for different modalities and categories. These results point to the importance of supporting drawing tasks in early years, as well as providing opportunities for discussing and interpreting representations. A methodological contribution of this research regards the combination of two complementary foci in the analysis of children's drawings that allows for a nuanced examination of their learning and abilities for meaning making.