Harvesting Corn

I've started letting Whip into the house for around an hour in the morning.  I remembered a friend would tell her dog she was leaving for work by saying the same words "I'm going to work" when she left.  The idea was the animal would eventually realize the phrase meant she wouldn't be back for awhile.  Decided to try it on the cats.  Before the dog comes in I locate the cats and say in a loud voice "Dog's coming in".  Dunder, who I consider warm and affectionate but not big on brains, gave my announcement a full throated  snarl yesterday.  Had he made the association?  Blitz hasn't (or maybe she likes trying to elude the dog).  Anyway, I said the same thing as always this morning and Dunder again snarled at me and took off.  Yesterday wasn't a fluke.  Tonight when Evelyn and Brent got back from their travels, Brent wanted to let Whip into the house.  I told them what I'd been doing and Dunder's reaction.  "Dog's coming in", I yelled.  Dunder snarled loud enough for both of them to hear and took off so now I have witnesses.  My working hypothesis is that cats are smarter than they let on.  They are probably concerned if we knew how intelligent they really are we would expect them to learn tricks.