Fruit flies and other simple organisms might seem like they’re creatures of instinct, governed by a set of basically predictable stimuli and responses. But fruit flies actually have free will. Depending on what your definition of free will is.Leaving philosophy aside, we know humans have free will because we’re able to evaluate a set of different options and make a conscious decision as to which of them we’re going to choose. But for animals, we can’t ask them how they go about making decisions, so figuring out whether they possess free will in a biological sense is much trickier.
I don’t know about you, but I think I could present at least some examples of people who appear to be “creatures of instinct, governed by a set of basically predictable stimuli and responses.”
But yeah, I’ve always thought the supposed distinction between free will and determinism is such a misleading way to frame the issue. We humans are able to visualize a set of options (within certain constraints) and choose between them because the type of brain we have allows for that sort of abstract thought. Other mammals have that ability to lesser degrees, so I’m not surprised that other animals might also have some ability to intelligently react to new situations. It’s a difference more of degree than kind.