Why are there a lot of insects at night? When do sharks sleep? Find out about what some animals do at night in this BBC Earth reader. The Ladybird Do You Know? graded readers series comprises a range of non-fiction STEM titles for young learners of English. Covering a variety of topics, Do You Know? adopts an enquiry-based approach, and includes motivating video content, project work and critical thinking activities to develop students' linguistic and twenty-first century skills. There are four levels progressing from CEFR level Pre-A1 to level A2. Each reader is accompanied by online video content, audio, video and comprehension activities, and suggestions for project work. Animals at Night, a Level 2 Reader, is A1 in the CEFR framework and supports YLE Movers exams. Short sentences contain a maximum of two clauses, introducing the past tense and some simple adverbs.