Pied Wagtail

It seems that this winter we are going to have the company of a pair of Pied Wagtails?
They appear during the day,picking up scraps that have fallen from the bird feeders.
Why they don't feed from the feeders I don't know?
But they are another welcome visitor to my garden anyway!
The Redwings have arrived as well.I saw 5 or 6 while out walking earlier.