Thebiteof a brownreclusespidercanbedeadlyandisknowntocausenecrosisinrarecaseswherethetissuearoundthebiteitselfstartstodie.
A bitefrom a blackwidowhasitsownsetofproblems, potentiallyleadingtolatrodectism, whichisanillnesscategorizedbymusclerigidity, vomitingandexcessivesweating.