Magic Wand selection flashing Question

[BW17]

When I use the magic wand to select in flood mode.  Sometimes when small disconnected fragments are selected and they flash on and off rapidly.   If I try to delete them they stop flashing but they are not dele ted.  I don't know what the flashing means and what I can do when this happens.  I'm guessing there is something I don't know.   I would appreciate help understanding what the flashing means.   See samples below off on off on off on

 

[toe_head2001]

You have a bunch of 1px sized dots, and thus the black-and-white animation of the selection outline appears as a flash.

 

The dots are not deleted, because they are not selected. Rather, the pixels around the dots are selected.