Fumigation is the making of toxic fumes. It may be done for several reasons. The most common use is to kill insects that hide in various places in a house or other building. There are a few steps to fumigate. First, the house or room is sealed. Then the fumigant (substance making fumes) is placed in the area. Then the fumigant is left to flow through the area. Finally, the fumigant is released before the people move back in. The gases are very toxic and the person fumigating has to make sure no one goes into the fumigation area or they might get poisoned.