1)
Why didn't Pharaoh's Chachamim to try to replicate Arov?
1.
Riva (7:11): Pharaoh did not call them, for he already saw from lice that the magicians could not do so.
2.
Moshav Zekenim (12): The magicians saw from lice that it is due to Hashem, and their actions will not help; it is a waste of effort.
