|Pileated Woodpecker on Double Tail-prop feeder|
I think your answer lies in the birds name. Woodpeckers, as their name suggests, peck on the wood of trees to look for or hide tasty treats, and to build nests. In addition to drilling holes, woodpeckers will knock their heads to send sound signals.
Their bill is composed of a number of separate horny plates called rhamphotheca which are made of a tough protein called keratin (the same protein that makes our fingernails).
It does wear down, but special cells on the end of the bill are constantly replacing the lost material. This keeps the chisel-pointed bill strong and resilient, while actually allowing it to be sharpened with every blow.
So you don't have to worry about frozen suet. Woodpeckers' many adaptations allow them to forage for bugs hidden under tree bark or suet or nuts offered from a feeder.
What’s the best suet for Michigan wild birds? http://bit.ly/tcKasp
Michigan made suet feeders: http://bit.ly/rbKskX
How many woodpeckers are in Michigan? http://bit.ly/tJ7e6S
Fun Facts about Woodpeckers http://bit.ly/tQ5lwt