From him from Ali ibn Al-Hakam from Al-Husayn ibn Abi Al-Ala who said:
I asked Abu Abdillah عليه السلام, peace be upon him, about a man who sees a snake or a scorpion while he is praying the obligatory prayer. Imam عليه السلام said: "He should kill them."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 355