Oscar and the moth : a book about light and dark / Geoff Waring. (OCLC #144228097)
In our Education Library, we classify many picture books as non-fiction, under the subject they are intending to teach. This book is clearly fiction (as our technician pointed out, that cat would have eaten that moth instantly!) but the intent is to teach about the scientific topics of light and dark, so it will be classified with this topic:
Dewey 535 is for “Light and related radiation”.