Treason of a Senator would be prosecuted by the executive apparatus, indicted by the competent DA or equivalent, and tried in an Article III court. When the charge is treason, the Senator can be arrested, incarcerated, tried, convicted and sentenced.
It's most likely that the Senate would expel a member who was convicted of treason.
My 'guess' is that the House has to vote before sending it to the Senate for the trial. Similar to impreachment.
Nope. Has noting whatsoever to do with the House. The Hosue/Senate interplay comes in for impeachment of executive (President or Officers) and judicial appointments. Impeachment is the legislatures power (the voice of the people) against an over-reaching, incompetent, or otherwise unqualified executive or judge.
Thank you so very much.
I'm not sure I still totally 'get it'. But as long as I know it doesn't work like Impeachment I feel like I've learned something.