- Eight story-based units
- Three double-page revision games
- A double page of stickers in the Activity Book
- Four cut out minibooks in the Activity Book
- 72 full-colour Story Cards illustrating key vocabulary
- 64 full-colour Flashcards to present or review new vocabulary
- 64 Word Cards showing key vocabulary
- Unit tests (one per unit) and three Progress Tests.

Big Bugs 3 and 4 take a more mature approach to learning with the adventures of the pop group The Bugs Band. Children discover the real world through cross-curricular related activities and more attention is paid to language and grammar specifically. In addition, there is a communicative syllabus with an integrated and balanced approach to all four skills.

Macmillan Children's Readers levels 3 to 6 can be used in conjunction with Big Bugs.