To control a millipede infestation, remove damp organic materials, such as leaf litter and mulch, that is located near the foundation of the home. Seal cracks with caulking to prevent the insects from entering the home. Remove live millipedes by sweeping or vacuuming them. Apply commercial pesticides around the foundation of the home and in cracks or crevices.
Store items such as lumber and firewood away from exterior walls, and move piles of rocks and organic matter, such as grass clippings, away from the home's foundation. Rake mulch back so it is at least 6 to 12 inches away from the foundation of the home.
If the grass is thick or unkempt, consider dethatching the lawn to control millipede populations, or mow the lawn frequently to keep grass as short as possible. To further reduce moisture, clean the gutters frequently, and inspect the downspouts and outdoor faucets for proper operation. Make any necessary repairs to eliminate water sources on the property.
Apply a recommended pesticide around the foundation of the home with a garden hose to ensure the pesticide penetrates the soil, or apply powdered pesticide to cracks and crevices where the insects enter the home. Rake mulch back before applying the pesticide to ensure the pesticide reaches the soil.