Environmental Hazards are one of the new mechanics introduced in Pikmin: Infection in Progress. All areas except Withering Terrace possess a unique environmental hazard that adds a new twist to the area. Environmental hazards have an array of effects that affect all entities in a variety of ways.
The environmental hazard Darkness is encountered in the Overrun Laboratory. Darkness affects the field of view much like Fog does, but to a higher degree. The President can only see a few feet around himself, but multiple light sources exist within the Overrun Laboratory, such as the beacons of Infected Scientists and the light emanated from Mushroom Pikmin.
Fog is an environmental hazard that acts much like Darkness, but to a much lesser degree. It is encountered in Noxious Expanse. The President can see much farther than he can in Darkness, although his vision is still impaired at a certain point. Many beings can emerge from the fog; caution in advised. A mighty beast prowls in the fog, and should be avoided unless it must be confronted.
Mud Patches are environmental hazards only seen in Polluted Creek, and are prevalent in the area. They slow down any small being that pass through it, like the President and his Pikmin. Larger beings, however, like Zombified Bulborbs, are completely unaffected by Mud Patches.
Radiation Patches are one of the most dangerous environmental hazards in the game. They are only encountered in Toxic Barrens. Any being that passes through them is slowly damaged, save for glowing beings, who are instead healed. Pikmin that enter Radiation Patches die shortly after entering them, and the President is slowly damaged over time until the Radiation Patch is exited. They can be identified as glowing green patches in the environment.
Spores are environmental hazards encountered only in Fungal Grotto. They appear from Common Glowcaps after disturbing them. The can also fall from the ceiling. After clinging on to an enemy, spores emanate a glow that makes them very obvious to any nearby creatures. Spores eventually fall off of the entity they clung on to, blackening and disappearing shortly thereafter.