The second part of Swarm will air tonight and David Tennant will again be narrating the documentary. Taking a look at some more of nature’s incredible invasions and looking at the intelligence of the animals involved, Swarm part two will have an approximate running time of sixty minutes. It will air tonight at 9pm on BBC One and be available on BBC iPlayer shortly after it's broadcast. Will you be watching the second part of Swarm when it broadcasts on television later tonight?