Vole

I've never seen a vole before.  My best guess is that this is a Southern Red-backed Vole.  This one shoots out of a small hole in the snow and grabs a sunflower seed under the bird feeder and then disappears back into the hole.  You can't blame them for being skittish.  They are low on the food chain, being a favorite meal of raptors, weasels and coyotes.