We are having an issue with our almost 6 year old daughter. Over the past few months, she has been cutting her 2 year old sisters hair. She only takes a snip or 2 at a time, but that's not the point. We have punished her by taking away things and giving her extra work to do, but that hasn't stopped her. We put up all the scissors, but I think she has a pair stashed away somewhere and won't tell us where they're at. She is becoming more and more sneakily about it, like hiding the cut hair, then taking it outside to dispose of it in the garden, since we where finding little piles of it after we find out she's cut again. For a almost 6 year old, she is pretty devious. My DW and I are our wits end. The 2 year old was late getting her hair, so this only makes it worse. We tried telling her to run away when sissy tries to cut it, but I think she sees nothing wrong with it, so goes along with what big sis wants to do. It's not like we're leaving them alone for hours at a time. The latest incident occured when my DW went out to get the mail. Now, I know we could eliminate the chances by not ever letting them alone, but that is not getting to the root of the problem. Any suggestions on how to correct this behavior?