I agree with Susan. If you wish, have a gander at this album for direct comparisons:
Downy Vs Hairy
This photo is perfect to figure out Hairy or Downy. Downy is 6.75" which is just a little longer than a suet holder. The Hairy is 9.25", much longer than the holder. Hope this helps. Learning the length of the bill will i.d. this for you.
Thank you Susan and Denis! And thank you Anne for your comment too. I will remember that now about the Suet holder the next time Woodpeckers are feeding at it.
Good call, Susan.! Basically to differientate between Hairy and Downy Woodpeckers, one hhas to imagine they can turn the bill back on the head. If the bill fits less then all the way to the back of the head, it's Downy. If the bill would reach the back of the head, it's Hairy. The bill on Hairy looks thicker and more substantial than Downy.