When not in use, it's retracted by a woodpecker, & it may wrap around under the skull, beneath the skin
[DOC] [TLE] Evolutionary morphology of the woodpeckers (Picidae) - Zobodat [PAR] woodpeckers not only possess a most outstanding suite of adaptive features ..... 
of the brain case on the upper jaw at the nasal-frontal hinge and its equal ... 
reaction forces by the tree on the bill during drilling can only be .... below, the 
compression in the skull base is a continuous ..... other as they wrap around the 
trachea.