auction question

[Earl Pippin]

While attending some auctions in my state of Florida, I have noticed that the bank representative starts the bidding off at $100.00, and nobody bids against him. Does this mean that there is more owed on the mortgage than the house is worth, and does this mean that the bank representative will go as high as what is owed on the mortgage? Is that the reason others don't bid against him? Thanks in advance for clearing this up for me.