Sa'd ibn Abdullah narrated from Muhammad ibn al-Husayn, from Ja'far ibn Bashir, from Abu Uyaynah, who said: Abu Abdullah عليه السلام was asked about a mouse that falls into a well. Imam عليه السلام said: "If it is removed, there is no harm. But if it has decayed, then [remove] seven buckets of water." Imam عليه السلام was also asked about a mouse that falls into a well and no one knows about it until after Wudu' (ablution) has been performed from it. Should the Wudu', prayer, and anything that came into contact with it be repeated or washed? Imam عليه السلام said: "No, the people of the house would have already drawn water from it and sprinkled it (around)."