Sony and Naughty Dog have kicked off a new developer commentary trailer series, with the first instalment offering an overview of the infected, the sub-human monsters of the game's post apocalyptic environment.

Wanting to differentiate from traditional zombies, the infected in The Last of Us are humans that have been taken over by a parasitic fungus, and the video explains how they have an echo-location ability they use by creepily clicking as they wander around.

The Last of Us is due exclusively on PlayStation 3 on June 14th 2013.