They are not representatives. They are trustees to the IMF.

They do not "work" for US at all.

James Trafficant spelled it out for us on 17 March 1993 in a speech he gave on the House floor.

Evidenced in Congressional archives. Still there to read.

Here is where to find and read it for yourself.

United States Congressional Record, Volume 33, page H-1303.

As well as, read Public Law 94-564, page 8, section H.R. 13955.

I don't know what my Mayor does in a single day

I don't even know what my Governor does in a single day.

I don't know what 1 city hall member does in a day

The original constitution had one representative for every 30,000 inhabitants, with slaves counting as 3/4 of a person, so the South wasn't screwed over in the original compromises that prevented dissolution of the union into separate states. It was looking like that was going to happen when the Articles of Confederation were not working well, and the nation set about to revise them (and got a constitution instead).

One for every 30,000 was fine for a small, primarily rural and agrarian, nation. One for every 30,000 would be the local elite in a typical small town today. It worked.

The size of the House grew as the nation grew, and eventually the number was fixed at 435 for the House by an act of law in the 1930s. I'm not sure its constitutional, but the Courts have seen fit to leave it alone.

Now, every member of Congress represents about 685,000 citizens, an impossible thing to do, as their constituents are too varied. The trade-off, however, is that if there were 9,933 House members (one for every 30,000 of our approximately 298 million citizens) then we would have a huge and inefficient legislature that wouldn't get stuff done. Then again, even that would be a trade-off of a trade-off, because inefficient legislatures mean bad laws don't get passed as well as good laws.