Book Borrowing Etiquette

Of course there's also the usual 'return in a timely manner' rule, but that applies to all borrowing, not only books.

Hot Chocolate

A delightful beverage, and very accessible ... unless you're allergic, or diabetic ... or until over-demand for chocolate outstips the supply and it becomes prohibitively expensive.

Squirrel Strategy

Of course, if you don't want squirrels, you could try doing the opposite of these things ... or move to Antarctica.