Episode 4

Chris Packham investigates mysteries and new discoveries from the natural world. He solves the puzzle of strange balls of worms on a road, and fish stuck in fences in Texas. He explains how an Australian town became plagued by giant bats, why so many sperm whales became stranded around the North Sea in 2015 and how the discovery of a spider in the Sahara could take us to other planets.

Finally, he reveals new discoveries, like a strange alien cocoon in the Amazon, a plant that makes a home for a bat in Borneo and he reveals how the discovery of scratch marks on a cave wall in Western Australia sheds new light on an ancient and terrifying mystery.