Actually, I think the scorpions may be in Sanhedrin, instead, near the Mishna about Ov and Yidoni and so on. It is interesting that the Rambam says that these things were just sleight of hand done to fool people into thinking that other religions were magical and to get people to worship Avoda Zara. He holds they were all illusions, and there is no such thing as real black magic.
