Cardinal In a Box

One delightful impact of our travel-related "cooldown" that led to a disappearance of the Finch Mob was the practical takeover of a window box...by Northern Cardinals.  The cardinals continue to surprise me.  Over time they took to tube feeders, suet feeders, visits in the high part of the day... all things I had been taught that cardinals don't do.  The poor things can barely land on and perch in this particular window box, but they do so anyway.  And they don't seem shy about pushing House Finches out.  The only trial left for them is getting used to the people on the other side of the glass.  I don't get too close, and they keep coming.  Eventually I suppose, they'll be less jittery.  What else will they do?