I have realized that there is a natural system of Checks and Balances in place in our house. Leave the table without pushing in your chair? Then you will find Casey climbing on top of the chair, using it as a ladder to climb onto the dining room table.. Where, if you leave a glass of liquid, Casey will spill it.
If you leave the kitchen gate open... or more accurately, leave the kitchen gate closed, but unlocked... Casey will manipulate the gate lock mechanism to open the gate, and going into the kitchen. Once he is in the kitchen.. well, picture a horny teenager at the Playboy mansion.. He can goto the tubberware cabinet, and dump all the tubberware on the kitchen floor.. Or he can grab the pots and pans and bounce them off the tile floor. Or he can go for the pantry, and rip everything off the bottom two shelves and throw them on the floor. Or he can head to the cabinet with the strainers and... yup spread them all over the floor.
If you leave the living room gate open.. you can lose Casey. Since he has recently figured out how to climb up and down stairs, once he sees that gate open, he bolts for the freedom, and might venture upstairs, or downstairs, or where ever he wants.
If you leave a toilet cover up, Casey will play in the water... Yuck.
If you leave a remote control anywhere he can reach them, you will return to the remote and find it soaking wet, and likely 'reprogrammed' thanks to random button pushing.