Hordes and Infestations

Hordes

A horde is a large group of zombies moving across the game, even if they are outside of your visible range. These hordes are formed when several smaller groups meet each other and become one, huge collective super-group. Average hordes are around 12-14 zombies together, though some may be bigger. Sometimes hordes are known to appear during defensive missions, and two hordes may join together which becomes more challenging.

Infestations

These groups are created randomly on a certain location. Zombies will begin to spawn in an infestation area, and you must defeat the required number of zeds, plus the required number of screamers to clear an Infestation. It is best advised to kill the screamers first to avoid more zombies joining.