Big Bug Books is a graded educational reading series for children ages 5-12, featuring the characters KIERIE & KRIEKIE. Big Bug Books (BB Books) specializes in the publication of children’s educational readers. The series is developed by Paula Raubenheimer, an occupational therapist specialising in child development and Dr. Hannie Menkveld, an educationalist. The books are graded from visual literacy (no words) to fluent reading. There are 4 colour-coded levels in the set, blue, yellow, orange and red and each book is colour coded and numbered.