Ask HN: How smart is your cat?

Inspired by this comment : https://news.ycombinator.com/item?id=30554638 Our cat could 'count', in that she knew how many people were at the dining table, she knew how many desert plates to expect. Only when she had them all, she would leave. We had another cat who couldn't : she sometimes would leave early or stayed while there were not desert plates left.