I had a cat that learned to open the door by watching us do. He would jump and grab the door handle with both hands. I guess one can conclude that animal intelligence is rare in all species
our two cats know how to open doors by hooking their claws underneath and pulling. we frequently come home to opened closets with folding doors. the girl cat always wants to go outside and stands up on 2 feet reaching for the latch on our sliding door while meowing and looking at us for assistance.
My rabbits can do this too. The noteworthy thing to me is that they're very good at discerning which side to pull even when encountering new doors. That is, they seem to understand the relationship to the hinge.
Door opening is common, I had several cats do it. One cat learned to vomit in the sandbox. We didn't train him to do it, he somehow understood the general vibe that we don't like him vomiting and decided to go to his sandbox to do it (and picked up on the positive feedback from that).
I wish we knew how to make them do that because he wasn't the only vomiting cat.
