Does diatomaceous earth actually work on ants?

How diatomaceous earth actually kills ants

Here's the part that makes it click. Diatomaceous earth isn't a poison, it's fossilized shells of tiny freshwater algae called diatoms, ground into a powder fine enough to dust but sharp enough, at a microscopic level, to be abrasive. When an ant, or a flea, or a bed bug, walks through it, those sharp edges scratch through the waxy outer layer that keeps its body from drying out. Without that coating, the insect loses moisture and dies of dehydration, not a chemical hit. That's why it's slow: it can take days for a colony to feel the effect, not the instant knockdown a spray promises. It's also why it stops working the moment it gets wet or humid, since dampness lets the insect's defenses heal right back up. The included duster matters more than it looks. DE only works where it's dry and spread as a fine, even film, so a puffer gets it into cracks and along baseboards where ants actually travel, rather than in the clumps you'd get shaking it straight from the bag. The food grade, additive-free version is also why it's fine to dust into a chicken coop or onto garden soil without worrying what's mixed in.