Forests and woodlands are the green lungs of the Earth and vital to mankind's survival. The air we breathe, the timbers we build with... the medicines we take. The list of benefits they provide is exhaustive. As is the list of other animals making a meal of these resource-rich environments.
While most of the series has focused on conflict, this episode is all about co-operation. The suitably named social spiders spin one enormous, 30m web for the whole colony, a queen bee rules her hive with a strict hierarchy and some green ants show great team spirit to help build a nest together. There are no broken societies here. David Attenborough shifts the focus to bugs that prefer cooperation rather than conflict. They include burrowing cockroaches, the suitably named social spiders - which share a 30-metre web.
The human eye is an amazing mechanism, able to detect anywhere from a few photons to a few quadrillion, or switch focus from the screen in front of you to the distant horizon in a third of a second. How did these complex structures evolve? Joshua Harvey details the 500 million year story of the human eye.