This movie scared my socks off.
Bette Davis is horrifying as Baby Jane Hudson, aging child star of Vaudeville. As the years passed, Jane and her sister Blanche (Joan Crawford) would become film stars. Blanche became famous and Jane was so jealous that she ran her over with a car resulting in Blanche living out her days in a wheelchair and ending her acting career. As the sisters aged, Jane took care of Blanche in Blanche's upscale Hollywood home. And Jane just got crazier and crazier.
Here's the dead rat scene: