They do. There is no question.It is just a matter of learning to read them.
Even cats can be happy, loving, playful, sad, angry, unhappy, and they can grieve badly, - to the point of dying.
I had two cats, siblings, very attatched to each other.
One of them died, and the other went through all the normal reactions: Chock, raw gief, denial, regrediation, depression and coming to terms.
It took 3 weeks, and the vet wasn´t too sure, that he would survive. Even 3/4 of a year later, when hearing his brothers name, he would run to the door, an afterwards sit very quiet under the table, looking sad for a couple of hours.
Birds are the same.
Non human animals, who, in addition, have a self awareness are among others whales, elephants and ravens, - and, no doubt, large parrots.
There are non human animals, who decorate, make aesthetic evaluations and use tools. Mice can put together instruments to reach a goal, imagine a technical solution, so to speak (I´ve seen it).
The great difference is, that they do it when nescessary, - we do it for fun most of the time.
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Femaline
Special Interest: Beethoven