My cat can open the drawer that holds her treats. One morning I woke up and looked over and she was in the drawer stuffing her face. I assumed that I forgot to shut the drawer after I gave her a treat that night. The next night I woke up when I heard a noise in the middle of the night, she was sitting on the desk trying to shove her paw into the handle of the drawer. I decided to not move and just watch her. She got her paw into the handle and pushed on it enough to open the drawer a crack. Then she shoved her paw into the crack she'd made and pushed until it was open enough for her to climb in. Now I keep her treats in a jar with a screw lid. She hasn't figured that one out yet.