Stanza from Roethke's "The Pure Fury"

This is stanza # 3 of 4 numbered stanzas, I was struck, real struck, by the line, A man's a beast prowling in his own house...


How terrible the need for solitude:
That appetite for life so ravenous
A man's a beast prowling in his own house,
A beast with fangs, and out for his own blood
Until he finds the thing he almost was
When the pure fury first raged in his head
And trees came closer with a denser shade.
                                    - From "The Pure Fury" by Theodore Roethke