Gopher is speaking figuratively, countryboy. Senators and Congressmen cannot be impeached. Impeachment is reserved for the executive branch (presidents, governors) and the judges.
If a Senator or Congressman misbehaves, the only remedy is action by the whole chamber (which rarely happens) or people throwing him out at the next election (which can happen if it is a swing district, but again, rarely happens in a safe Republican or a safe Democratic district).
"...throwing him (tsk, tsk - you forgot "or her") out..." - Do you mean that figuratively or literally? Or in a "just kidding" sort of way? I'm not that quick on the draw, so you'll have to be patient and go slowly so I have a chance to catch up with you. Thanks.