In this episode, Winterwatch looks at the extraordinary lengths animals go to in order to survive this harshest of seasons. Chris Packham is live in the New Forest, looking for Dartford warblers as well as updating us on what’s happened on the live cameras over the weekend. Iolo Williams is looking at the water shrews and discovering their amazing ability to survive the winter. Meanwhile, Gillian Burke is at a sewage works close to RSPB Old Moor, meeting the wildlife that call it home, and Michaela Strachan is looking for whooper swans at Tentsmuir in Fife. Tonight sees the start of Megan McCubbin's four-part look at species that aren't as loved as they should be. Megan is hoping to challenge the reputations of these animals and make us appreciate them – starting with rats. We’re also on the Somerset levels as Birdgirl Mya Rose Craig goes in search of the very rare Penduline tit – and she’s hoping to show Iolo where to find them.