Simplify the following text for a Grade 7 native English-speaking person.
Original: This was cut in the early 17th century to allow entry for the Bishop 's cat to deter vermin that were attracted to the animal fat used to lubricate the clock mechanism .
Simplified: This was cut in the early 17th century to allow entry for the Bishop 's cat to deter vermin . The vermin were attracted to the animal fat used to lubricate the clock mechanism .