1,101. Mice Entering and Exiting a House

Chometz u’Matzah 2:13

Let’s say that a mouse entered a house with a piece in its mouth, then a mouse left with a piece in its mouth. In such a case, we assume that it’s the same mouse and the house need not be searched again. If the mouse that entered was black and the mouse that left was white, it must be searched again. If a mouse entered with a piece in its mouth and a weasel left with a piece in its mouth, the house must be search again. If a weasel left with a mouse and a piece in its mouth, it does not have to be searched again, as this is assumed to be the piece that was previously in the mouth of the mouse. If a snake enters a hole with a piece in its mouth, there is no need to fetch a snake handler to remove it.

Chometz u’Matzah 2:14

If chometz is on a high beam, one must get a ladder and remove it because it might fall. If chometz is in a pit, one is not required to bring it up. In such a case, all one need do is to nullify the chometz in his heart.