Will seven dust kill bed bugs?

I believe you are referring to "Sevin Dust," a powerful insecticide. Its advertising says it will kill most kinds of insects, but there are several things to keep in mind. The strength you can get over the counter may not be enough to do the job. And in the case of bed bugs, more needs to be done than just spraying. You need to find the source of the infestation and get rid of it. It is often useful to call in a professional exterminator: they are allowed to use more powerful and more effective methods and they have lots of experience with bed bugs. Letting a licensed professional do the job will be more expensive, but you will get longer lasting results.