Not a Bird

Friend Nancy came over and left her car here.  We went shopping in my car for most of the morning and then before she left she came into the house.  She was admiring the view and all of the birds when she suddenly went "ooh" and screwed up her nose.  I looked out and saw a little triangular face looking up over the edge of the deck.  It was joined by another and eventually there were a total of four (that I saw anyway).  They deftly shinnied up a shepherds hook to the bird feeder and began indulging.  I should be repulsed but they are pretty cute and, more importantly, they are outside.  I don't like to kill things that are outside if it's not necessary.   I can figure out something to keep them away from the bird food.  The cats will use them as play toys should they make their way into the house.  The weasel and harrier would love to have them for lunch.    If it does become necessary I've got poison pellets which don't harm cats and dogs but will make short work of the mice.  In the meantime, I think these are deer mice.  Nancy said these looked bigger than house mice (the other species of mouse indiginous to the area).  Deer mice excel at climbing, have lighter colored fur on their bellies, and tails shorter than their body length.