"Dead!Fred is dead, but his death is quickly drowned out by Aragorn's Aragog's spider bebes, who have somehow inexplicably joined in the fight. Now, I haven't been reading the rest of the chapters very carefully, but, um, what? Why do we all of a sudden have spiders attacking Hogwarts? If I remember Book Two right, the spiders said that they'd eat anyone who came within eyeshot."

Not to mention that in Chamber of secrets Aragog told that all spiders, including Acromantulas, fear the basilisk above all other living things. So, in DH we should believe that when Voldy (who represent serpents and basilisk, and who has had basilisk running amok twice) calls they come?