I thought things like mirror tests don't work on cats, because they are such assholes they actively sabotage such experiments. For a time it was even thought cats were very dumb, but later tests have shown them to be actually very smart.
I heard a pet behaviorist explain the mirror test for roosters/chickens had to be designed with consideration for them being social animals. They found when putting a mirror without other chickens around, the roosters wouldn't crow when a predator was flying overhead. Yet, with other chickens there, they did