Clickers are the semi-deceased corpses of humans and animals that have been infected with a nanite-plague that uses their muscles and skeletal structure as a locomotion and delivery device.
Clickers are so named for an almost toy-like mechanical ticking, whirling, and clicking sounds they make when they move or become active, other than this they (disturbingly) make no noise whatsoever. Clicker’s are drawn to loud noises and many have been infected while in the heat of an argument or otherwise un-aware of the clicker’s advance. Clicker’s appear as the creatures they once were but with techno-organic components jutting from their skin, and shimmering blackish nanite liquid dripping from their orafaces and open wounds.
Unlike zombies in ancient movies or television programs, they are not killed when a head-shot is scored, almost nothing will stop their advance. shattered bone will only be repaired within minutes, damaged muscles or organs do almost nothing. Only bathing them in fire is a sure way to kill a clicker, otherwise your just slowing them down.
Clickers can infect humans and other animals with blood/nanite fluid exchange, but recently some travelers claim the clickers no longer need to touch you to infect you, that they have evolved a form of micro dart that is fired through unknown means and if the dart penetrates the skin infects it infects the host with the virus. regardless of if this is true or not, most survivors avoid clickers like… well… like the plague.
After being infected (the victim may be aware or un-aware of the infection) the host will soon become very sleepy, slightly paranoid, and sensitive to light and heat. They will be compelled to find a cold dark place away from others, will pass out, and within just a few short hours “die” and become a clicker themselves. Currently there is no known cure once infected. Clickers will often lye in a coma like state in a dark area until a loud noise awakes them, in which case they will send out some form of signal that awakes other near by clickers and advance in-mass against whatever it was causing the disturbance, so if you just fought off some Clickers and your buddy bobby hasn’t been seen for hours… probably not a good idea to be the first guy to check the basement…
Clicker’s remain a serious threat in most destroyed large cities, but after the ceasing of the attacks by the aliens, for no known reason, they “mostly” stopped forming hordes and walk-dragging themselves around the country destroying any human habitation.
It is unknown if the clicker’s were originally an attack by some form of techno-organic alien life form or if they were some how created by humanity as a response to fight the invading aliens.
There are also rumors that the reason Clicker attacks have reduced greatly in number and frequency is because in the deepest portions of the ruined cities the clickers are actually building things, other rumors exist that there are giant clicker monsters made up of hundreds of bodies and random wreckage but again, accounts like this are not generally believed, Clickers being dangerous and unstoppable enough without resorting to giant monster status.