Here is chart of the Bid to cover from latest 4 week Auction it stands at 10.72. So for every offer there is 10.7 bids,Think about that for a second.

Yield is Zero  has been for last few auctions.This is all to do with worries about breaching  the debt ceiling,treasury is selling less short term notes until a resolution  or extension is found before December.In time of financial panic we have seen moves like this