The Victor Fly Magnet Replacement Bait 3 pack for M382 Fly Magnet (M383) is for use in an outdoor area only, and it would trap and kill the flying insects that pass in the area, not the nests. 

We recommend using a general insecticide like Bifen IT mixed with an IGR to provide you relief. The Bifen IT can be used both indoors and outdoors, but it will only kill the adults as the larvae is protected in its egg form. To control the larvae you would need to mix the NyGuard IGR (birth control) in with the Bifen. NyGuard is labled for fungus gnats as well as a large variety of other insects to sterilize the adults from being able to lay viable larvae. This will control the population drastically in keeping new ones from developing. You should mix 1 ounce of Bifen with 4 ml of NyGuard IGR to each gallon of water you use. Bifen IT can be used as a broadcast over the entire lawn or just as a perimeter treatment. We recommend spraying on the outside of your home on all the window and door frames and on window screens to try and prevent pests from entering your home. In the bedroom, spray as crack and crevice treatment and focus on damp areas.