I'm happy, to an extent, when our (16 to 18 year old) students re-shelve the books they've been using when they're finished. It makes my job very slightly easier, provided:
a) they take the alphabet into account;
b) they take the Dewey Decimal system into account;
c) they accept that books on a shelf go a particular way up;
d) they accept that books on a shelf should have their spines facing outward and their pages facing inward;
e) they agree with me that shelved books should be fitted between other books, and not on top of them, underneath them, around them, inside them, slumped horizontally at the end of the shelf or some ghastly combination of all of the above.
If a student doesn't feel able to go along with all of the above, then frankly I'd really rather do it myself.