Use pest repellent sprays and traps to get rid of existing insect problems. Fly paper, bug sprays and ant traps can all help to reduce the number of insects within your crawl space. For especially bad insect problems, consider fumigating your house or using a bug bomb in the crawl space.Click to see full answer. Besides, how do I keep bugs out of my crawl space? Spread a crawl space vapor barrier. Vapor barriers can prevent moisture from condensing on wood. Use crawl space encapsulation. Encapsulation allows you to seal the ground, supports and underside of your house with a high-density liner. Install ventilators. Beside above, do roaches live in crawl spaces? When indoors, they can be located in dark, moist areas like basements and crawl spaces. Other likely areas indoors would be around bathtubs, floor drains, and sewers. Outside the American Roach can be found in moist, shady areas like yards, hollow trees, woodpiles,and mulch. Also to know is, can I set off a bug bomb in my crawl space? BTW, you will need to toss one bug bomb for every 2-300 sq ft of crawlspace. spread them out under there and close off each access panel after you toss them in. leave it sealed for an hour or two, then open and let it air out. you can work under there within 4 hours of bombing.How do you get rid of critters in a crawl space?? Never store food items in your crawl space. Put a ?? light in your crawl space. Eliminate water and humidity. Use a “rat slab,” a thin plate of metal, thick plastic, or stone, to deter tunneling rodents. Seal any holes or cracks.