I should have mentioned that my grandmother (who was in her late 40s back then, so not physically or mentally unable to deal with garage doors) had this install

I should have mentioned that my grandmother (who was in her late 40s back then, so not physically or mentally unable to deal with garage doors) had this installed because she was afraid of mice and didn't want mice getting into the garage. I think she imagined mice running in from the bushes if she left that door open too long. She wasn't worried about human intruders 50 years ago in Huntington Beach. Today she would probably have to worry a lot more about that possibility.