The purpose of many animal studies at early grades is to build observation skills, develop a knowledge base, and practice age-appropriate science skills like comparing, describing, and drawing. While these are important learning experiences, the National Science Education Standards also recommend that students engage in scientific inquiry (NRC 2000). In this article, a team of educators, curriculum developers, district administrators, and scientists believe that it is possible and beneficial for even the youngest students to participate in a rigorous scientific inquiry that builds a conceptual understanding of animals and the nature of studying animals. So, to test this idea, they created an inquiry-based unit on animals, implemented it in kindergarten classrooms, and observed the students' responses. Their unit focused on guiding students to formulate explanations about animals based on scientific evidence. They wanted their students to use direct observations of animals as the primary source of evidence for their explanations about animals' needs, structures, behaviors, and relationships with the environment. (Contains 2 figures and 4 resources.)