Cats are smart
I live in a highrise apartment so my cats are indoor kitties. Sometimes the oldest will get an urge to "run away", and when I open the door she darts out into the hallway. Talk about a confused look on her face. She comes back in right away, hehe
My youngest cat used to open the freezer on my fridge. I got her at 4 months old and was home for the first week that I had her. One day when I returned home from work I found the freezer door (fridge with the freezer door on top), wide open and all of my ice cubes melted. I closed the door and tried opening it again and it was quite firm. I just figured that I had forgotten to close it properly and when one of my cats jumped onto the counter, then the fridge top and then the top of the cupboards, that they accidently pushed the door open.
This happened a few times, and I know I wasn't that careless to keep leaving the freezer door open.
One day I was in my living room and heard this horrible banging sound coming from my kitchen. I went in there and there was Abby hanging off the front of the freezer door and bouncing her hind legs off the door and swinging her body side to side. And she managed to open the door!!!!!!!!! I looked into the freezer to see what was so interesting in there, and found some catnip that I had put in there so it would stay fresh.
It seems that she smelled it and wanted at it, but once she got the door open she couldn't figure out how to get into the actual freezer to get to the catnip, LOL I started to tape my freezer shut after that, and she stopped doing it.
My oldest cat has figured out how to open a cupboard door so she can sleep among my pots and pans. I hope I'm not the only one who has to wash pots before and after cooking, LOL
Abby has also figured out how to open the draws beneathe my waterbed. She likes to climb into one and sleep because it's extra warm.
I'm sure if they were taller they would be able to open doors using door knobs!!!