Wow - learn something every day. Didn't know there was such a thing as book lice. Don't think I wanted to know (:
BTW - put me in the eeewwww category re: bugs & if 2 rooms had them, I'd probably switch hotels as well.
Plus, you might want to notify Marriott HQ (not to ask for compensation), but to say there appears to be a bug issue w/ one of its properties & the GM didn't seem to be addressing it. Something like that.
Cheers.