Harris 8 oz Diatomaceous Earth Crawling Insect Killer, Indoor & Outdoor Powder

Made from 100% freshwater diatomaceous earth, Harris Crawling Insect Killer works by physically damaging insects’ outer shells and dehydrating them on contact. The ready-to-use powder is designed for indoor and outdoor use, and its built-in puffer tip helps direct treatment into cracks and other narrow hiding places.

Use it around areas where crawling pests travel, such as garages, basements, attics, gardens, and entry points. The powder remains effective while dry, making it a practical alternative to a spray when you want to treat a dry crevice or create a powder barrier.

Who it’s for

This product suits households looking for a diatomaceous earth treatment for ants, roaches, bed bugs, fleas, earwigs, silverfish, spiders, and other listed crawling insects. It can be applied indoors or outdoors, so one format can serve pest-control tasks in rooms, storage areas, garages, and garden spaces. The formula is made with freshwater diatomaceous earth and no additives, use it as directed around children and pets.

For a typical application, use the puffer to place a light, targeted amount in cracks, crevices, or other insect pathways instead of spreading powder over exposed surfaces. In living areas, avoid creating airborne dust or leaving deposits on exposed surfaces. If treating a surface, test a small area first to check for staining or another adverse reaction.

Tech summary

• Product: Crawling insect killer powder
• Size: 8 oz
• Material: 100% freshwater diatomaceous earth, with no additives
• Application: Built-in puffer tip for targeted placement
• Use: Indoor and outdoor, remains effective while dry
• EPA registration: No. 3-18

Pros

The main distinction is its mechanical action: insects that contact or ingest the powder are affected through physical abrasion and dehydration, rather than a chemical killing process. The dry-powder format is useful where insects hide in tight gaps, and the narrow puffer tip helps place it in those areas. Manufacturer information states that insects die within 48 hours of contact or ingestion.

Need to treat a crack or crevice rather than spray an open area? This powder’s targeted application makes it suited to that kind of placement. Keep it dry where applied, moisture affects how long it remains effective.

Buyers commonly describe the product as effective against pests such as roaches and ants, while feedback on application is mixed. Some appreciate the applicator, and others say dispensing the powder can be messy, some also report lung irritation from dust. Apply carefully and avoid breathing airborne powder.

Should you buy it?

Choose Harris Diatomaceous Earth Crawling Insect Killer if you want a ready-to-use powder for treating insect pathways and hiding places indoors or outdoors. Its freshwater diatomaceous earth formula, puffer-tip application, and continued effectiveness while dry make it especially relevant for targeted treatment in cracks, crevices, and other dry areas where crawling insects are found.