Equipping cats and dogs with talking buttons (see, for example, https://www.youtube.com/playlist?list=PLBh-BXgsO9IjhN-thTLvm... or https://www.youtube.com/@floundercat) has shown me there is a lot more going in their little heads than I suspected. There are examples of cats describing their dreams, or worrying about what will happen in the future, or theorizing about the nature of the world (in a very naive way).
Birds have higher neural density than mammals (https://www.pnas.org/doi/10.1073/pnas.1517131113) so can pack a lot into their tiny heads. I do wonder what they'd have to say, if given the chance.