What's the difference between diatomite and bednug?

Diatomaceous earth : Or diatoms are small creatures in the ocean. A bedbug is a big insect which bites and causes skin lesions if they are in your bed. They can live without blood (which is what they eat) for months.

Bed Bugs: Diatomite, also known as diatomaceous earth, is the naturally occurring fossilized remains of diatoms. Diatoms are single-celled aquatic algae. Bedbugs are reddish brown, oval and flat, about the size of an apple seed. During the day, they hide in the cracks and crevices of beds, box springs, headboards and bed frames. If you have bedbugs in your home, professional extermination is recommended.