Tiny Black Insects in the Basement Around the Windows

Types

• Millipedes are worm-like pests that are dark brown or black in color. Most millipedes are smaller than 1 inch in length and have multiple legs. They are found indoors in the fall months, typically moving into basements and cellars after extended periods of wet weather. Ground beetles are often seen inside basements and usually enter homes through cracks in foundations or through crevices underneath window sills. These black beetles do not bite or sting humans, nor do they damage clothing or furniture. Ground beetles range from very tiny to large, and they have a flat, elongated shape. Some ground beetles are tan, brown or black in color, and they are hard-shelled.

Effects

• Millipedes are harmless to humans but can become a nuisance when they move into homes in large numbers. These multilegged pests feed primarily on organic matter such as leaf litter and plant roots. Millipedes have high moisture requirements and die quickly after moving indoors. Those who are living in damp basements may live a bit longer due to the high humidity. Ground beetles feed on insect larvae and are not damaging to the structure of homes or furniture. These beetles may be drawn to windows because they are attracted to light.

Cultural Control

• Keeping millipedes and ground beetles outdoors where they belong is best accomplished by sealing all cracks and crevices in your basement with caulk. Removing leaf litter and plant debris from around your home's foundation may also help reduce infestations of these annoying pests. If millipedes are chronically infesting your basement, reducing the humidity level may help. Placing a dehumidifier in your basement will lower humidity levels, making it a less desirable home for millipedes.

Chemical Control

• If millipedes and ground beetles are persistent, you may consider spraying an insecticide around the perimeter of your home to reduce infestations. Pyrethroid insecticides containing active ingredients such as cyfluthrin or bifenthrin are often effective in reducing infestations. Spraying these products around the perimeter of your home may prevent insects and pests from entering.