When you empathize, you imagine yourself in that situation and feel for the creature. It doesn't matter whether the creature has the capacity to react as you would or not. Empathy is an emotional reaction.
Wouldn't it be more sympathy then empathy? You aren't really feeling what the spider feels. In this specific case you would be feeling a good deal more emotion then what the spider feels, in many cases involving humans it you would probably feel less, and in both cases whether it is more or less what you really feel is different.
Tim
ympathy
\Sym"pa*thy\, n.; pl. Sympathies. [F. sympathie, L. sympathia, Gr. ?; sy`n with + ? suffering, passion, fr. ?, ?, to suffer. See Syn-, and Pathos.] 1. Feeling corresponding to that which another feels; the quality of being affected by the affection of another, with feelings correspondent in kind, if not in degree; fellow-feeling.
They saw, but other sight instead -- a crowd Of ugly serpents! Horror on them fell, And horrid sympathy. --Milton.
2. An agreement of affections or inclinations, or a conformity of natural temperament, which causes persons to be pleased, or in accord, with one another; as, there is perfect sympathy between them.
3. Kindness of feeling toward one who suffers; pity; commiseration; compassion.
empathy
n : understanding and entering into another's feelings |