Can animals ‘think about thought’?

I thought from reading the headline that researchers were claiming that nonhuman animals might approach having a ‘theory of mind’, the implications of which would be earthshattering. But it turns out they use ‘thinking about thought’ to mean something different and far less momentous. They give nonverbal memory tasks to animals like dolphins and rhesus monkeys but the study design gives the subject the option of declining to complete a task they assess as too difficult, which the researchers take to mean that the animal knows when it doesn’t know. —Guardian.UK. I have not read the study but it strikes me that there are probably behavioral explanations for the subjects’ behavior in the test that do not require us to infer self-reflective abilities. On the other hand, why not? I don’t know. [Now where’s my fish?]