Keep mine locked all the time overnight. Mind you reminds me of a funny story. Was out cleaning when the dustman came round. When I came down off my ladder went to dip in my bucket and it had gone. Put 2 & 2 together ran after the dustcart and they had chucked my in my bucket water an alll. Would have thought the ladderneither me up it would have given it away but saw the funny side. Now I laugh when people moan that there dustman didn't take there bin coz they had put the wrong thing in it