

Chickens.
But they’re also dumber than you might realize at the same time.
They’re a paradox. Capable of surprising feats of brilliance to obtain food. Amazingly companionable. And dumb as a sack of rocks.
No, I take that back, a sack of rocks might actually be smarter in some ways.
It comes down to them being driven by instinct far more than thought. They’ll follow instincts to their own detriment, but can still be good problem solvers given time and lack of interference. But their own brains can provide interference. It’s kinda like the inaccurate but somehow true “squirrel” meme for ADD. If their little pea brains take note of anything else while trying to do something, chances are high they’ll forget the original goal.
However, sometimes, they’ll get so fixated on something they just can’t let go prevent them from getting or doing something better.
So a lot smarter than most people think, but still on par with turnips for brains.
I first that joke in person in elementary school, in the eighties. I had read it in a book a few years before that. Maybe the third grade? Coulda been fourth.