How to kill insects smaller then lice and fleas?

To kill insects smaller than lice and fleas, you can use a mixture of water and dish soap sprayed directly on them, as it suffocates the pests. Additionally, diatomaceous earth can be sprinkled in areas where these insects are found; it dehydrates and kills them upon contact. For persistent infestations, consider using insecticidal sprays specifically formulated for small pests, ensuring to follow safety instructions. Always target the source of the infestation and maintain cleanliness to prevent future occurrences.