Eating Miscanthus

I've put 2" or 3" of miscanthus down in the run to mop up some of the sogginess, which is working well so far. The chooks seem to love it and I see great swathes of the stuff flying from one side of the run to the other!
BUT - they also seem to be eating it, which surely can't be a good thing. Do you think this is just a passing phase because it's new, or should I rethink the whole idea? Has anyone else found similar?
I'm also hoping they don't decide to lay in it and abandon their nesting boxes!
It's a commercial brand (F...Fibres), chopped and dust extracted - and just to plug it, a £6.74 bale goes a long long way!
BG