They do- IIRC, all garage doors use 'code hopping' to prevent others being able to open a door. However, if you check into the ways the sneaky bastiges watch and wait with their code sniffers, it's not hard for them to get in. Also, unless the place has cameras, it's not difficult to open a door if the red pull cord is still hanging from the release- If you want to know how, PM me. Once they get in,m they can teach the opener the codes for their opener.