I guess I've seen the same in Cattails in the winter.  Perhaps a good bug 
hangout?

A local Red-Bellied fledgling has started to learn how to eat from 
my "Squirrel Buster" feeder this week.  The woodpecker looks pretty awkward 
hanging from the perch, but it seems to be working for him. Most of his 
body is hanging low on the perch, but his head and bill are large enough 
that he can get in there and grab a seed or nut at each visit.

Denise Ryan
Cheverly, MD
savetheocean at yahoo.com