http://books.google.com/books?id=Zk7f_SKDqHQC&pg=PT75&dq=feet+tickle&hl=en&ei=nU3gTOPNBsSAlAf91924Aw&sa=X&oi=book_result&ct=result&resnum=2&ved=0CCkQ6AEwATigAQ#v=onepage&q=tickle%20tickling&f=false