In general it may be the latter. Portia spiders in particular, though, will observe a target, observe their surroundings, then navigate a complex path around an

In general it may be the latter. Portia spiders in particular, though, will observe a target, observe their surroundings, then navigate a complex path around and through structures that block their vision of the target to reach a destination that will allow them to attack it. Suggesting very much that they form some kind of model of their surroundings, plan a path through it, and remember that path.