Using any smoke deterrent indoors is not recommended. Outdoors The Giant Destroyer Super Gasser can be used in holes, tunnels, burrows and in underground areas where rodents such as rats may be living or nesting. This product will not kill rodents unless they are trapped in an area die of smoke inhalation. In most cases, they will be alarmed by the smoke and run away from the burrow. In this case we recommend sealing the burrow with rock such as gravel or lava rock so that they cannot dig it out. use 1 Giant Destroyer per tunnel as needed making sure that the any outside escape holes are filled or sealed prior to using. Again, do not use this product indoors, in an attic or sub area under a house or building. It is for outdoor use only.