I was in the sewers in Hydlaa earlier today, and I attempted to fight a rat. Unfortunatley, a red message appeared on my screen reading  "Rat is impervious to attack". Also, my friend (Rakorian) had the same occurance while trying to fight gladiators nearby. Atlhough I was overjoyed to find a good number of rats inhabiting the sewers, I was still thoroughly disappointed.   I'm wondering if anyone else has experienced this problem.