It has a transitive use (the object being the things being seized) and two intransitive subtleties:

 1b.intr. To plunder; to seek after or for spoil or booty; to go about with intent to plunder; (later also more generally) to maraud, rampage.

2a.intr. To eat voraciously; to feed hungrily or greedily; (also) to prey on or upon. Also fig.

It is used intransitively in our work.

• 17.054 There a host of Wargs came ravening

“raven, v.” OED Online. Oxford University Press, June 2015. Web. 25 June 2015.