An informative book about animal behavior that provides various levels of accessibility:  for the youngest students, a rhyming couplet (in large font), supported by illustrations, provides the basic information on each type of tool-using animals; for interested audiences, a paragraph in smaller print goes into more depth to describe the tools mentioned in the couplet; for particularly curious students, the end-pages at the back of the book provide even more details.  On the opening page, as well as in the end notes, it does say that there is no agreed-upon definition within the scientific community as to what constitutes tools and tool usage, and states that for purposes of this book the author was including any object an animal uses to accomplish a goal.  This is a pretty broad definition, which allows the inclusion of several animal behaviors that would be open to debate as to whether or not they really count as tools, but I think it’s good to engage children in the debates of the wider academic community, so that they know science is not completely cut and dried.