Even though the White Breasted Nuthatch is, by far, the most common Nuthatch here in NW Arkansas, in some years the Red Breasted Nuthatch comes to our area for the winter from the Northern US. The White Breasted Nuthatch is larger and stronger and the Red Breasted is smaller and faster. I have both species in my yard in Murray Valley, this year. Their antics are always fun to watch; they cling upside down, go down trees head first, grab seed and fly away, and both call with an unquestionable “YANK-YANK”. I have included photos taken from my home of both species (Canon 7D with EF600L f/4.0 Lens); White-Breasted first; Red-Breasted second:
Life and Wildlife along the Little Buffalo River 
I have these on my feeder, but I didn’t know their name. Thanks!