Um..I wouldn't call it dumb...well..I'd call it dumb, I guess.
My dog, Lola, sometimes we'll be standing in the hall and she'll have a toy in her mouth. If I step forward to act like I'm going to grab it, she turns around the opposite way of which she SHOULD turn and runs head on into the wall. It's happened so many times.
My cat's smart. My hamster is very smart, for a little rodent, too!