Does diatomaceous earth kill all bugs?

I've heard diatomaceous earth is good for getting rid of bugs. Is that true?

Diatomaceous earth (DE) can be effective against certain crawling insects, including ants, cockroaches, fleas, and bed bugs, but it's not a universal fix. It works best on soft-bodied or thin-shelled insects that come into direct contact with the powder. Flying insects are largely immune. 

The most important thing to note with DE is that the powder has little impact on eggs or larvae, so it won't stop an infestation at the source. And it will only work on those insects that come into contact with it, so will rarely resolve an infestation.

How does diatomaceous earth kill insects?

When a crawling insect walks through DE, the powder sticks to its body and scratches through the waxy outer layer of its exoskeleton. Without that protective coating, the insect loses moisture rapidly and dies from dehydration. It's a physical process, so insects can't build up resistance to it the way they can with some chemical treatments.

Diatomaceous earth can handle a few wandering bugs, but it won't get to the root of the problem. If you're seeing them regularly, there's likely a colony nearby that needs professional pest control.