Two's company, three's a crowd

I am not sure what the minimum number for a flock is but I suspect it is more than three.  I don't normally take photos on the feeders and don't normally have the feeders all in a line but there have been a lot of woodpeckers in the garden recently - up to five at a time - so I have been trying to get as many as possible in one photo.  This is the best I have managed so far.

If I can get four that might qualify for a flock.