Right beneath our feet is a secret world of disguise and espionage, social networking and courtship, rape and pillage, parenthood and relationships. The terrestrial arthropods - the bugs - are the most dominant animals on our planet. They outnumber us in their hundreds of billions and have survived for 500 million years. They have outlived every catastrophe Earth has thrown at them, seen the dinosaurs come and go and even witnessed our own arrival. They are so intrinsic to the natural world that without them we would struggle to exist. Sir David Attenborough takes us deep into the macroscopic world of bugs, uncovering their marvellous adaptability from the primitive evolutionary design of the millipede through to the graceful apex predators that exist today. Descending into the watery depths to witness aquatic battles, he also explores intricate spider webs and gets closer than ever before to the fangs and claws that create this fascinating world.