Finally some intelligent replies.
You asked a question and potentially preemptively excluded a possible answer with no justification, regardless of how well someone might try to put it forward or explain it.
I wouldn't even propose free will as an answer but if the question is as lazy as that then expecting intellgient, well thought-through answers seems a bit rich. It is at best lazy and at worst purely intellectually dishonest, and somewhere in the middle is presumptuous to ask a question and state that certain answers don't count regardless of what anyone says.
Maybe that's something to consider when becoming indignant at the lack of intelligent replies that take other people's time and effort to formulate.
As to your question, define "think"? The answer can vary between yes or no depending on what is counted as thinking, for example, if solving simple problems counts as thinking, then yes, many animals do think, as some of them are clearly capable of figuring out how to open doors, or move things to access food.
If perhaps you mean they are capable of processing information and adapting their behaviour accordingly, then yes, they can, how else could you train a dog if they were incapable of recognising positive and negative reinforcement?
In my opinion, to give a yes/no answer, which is completely objective, a completely objective definition of "thinking" is required.