Today two household humans and a non-dog-owning visitor witnessed Penny solving a spatial problem. She had been outside with us as we looked around the garden and she missed out on coming in through the door with us, so she had to come in through the little swinging doggy door.
But there was a problem. Penny had a stick in her mouth and the stick was too wide to fit through the door. She tried a time or two but got stuck. So she took a grip on one end of the stick and tried to open the door with it, but couldn't get enough pressure on the swinging door to make it open. We stood and watched her, convinced there was some level of problem-solving occurring. However, it seemed more of a trial-and-error process than a logical thought sequence.
But...she stepped through the door without the stick, seemed to be considering the situation and then pushed the door open with her head, grabbed the stick end-on and pulled her head back into the room.
It sure looked like problem-solving to us.
Here's the door.
And here's the stick after some enjoyable chewing. (It was a soft stick so we thought it was safe to leave her with it. Anyway, any dog who had worked so hard deserved the enjoyment of the fruits of her labor.)