Centipedes in the house in large numbers are a moisture problem. Centipedes prefer to locate in dark, damp locations. Finding the habitat is going to provide the source of your dilemma. If your dehumidifier is pulling over a gallon of water a day, there could be a damp area you are missing. The breeding ground could be hidden under the furnace, under shelving, built-in cupboards, or even behind wall paneling.
Even after basement waterproofing, bi-monthly professional extermination and a dehumidifier in the basement, there are always corpses in the basement and then soon after, live ones arrive in the basement and on the first floor.
If you have been ‘pest controlling’ the centipedes in the basement, try addressing the problem from outside the house. Remove any organic debris and mulch from around the house and try to keep this area as dry as possible. Caulk and seal up all cracks in the foundation and freeze-board around the home. The freeze-board is the lowest trim of wood or aluminum siding where it meets the foundation.
You may find the source of centipedes in a crawl space adjacent to the basement, in wood chips alongside the building, under a woodpile or broken concrete. Other nesting areas include cracks in cement walks and stoops, slab sheds, and compost piles.
Use pest control poisons on the foundation wall and the first foot or so of ground around the home. Residual insecticides available to homeowners include trigger spray “home pest control” and boric acid dust. But, centipedes should not be controlled with pesticides away from the dwelling. Centipedes feed on small insects, insect larvae, and on spiders. Consequently they are beneficial, though most homeowners consider them a nuisance.
Centipedes are poisonous, but their bite is seldom worse than a wasp sting. If you are at all allergic to bee or insect bites get medical attention immediately after being bitten by a centipede.