When I sold my house a few years ago, I couldn't find the key either. I had Rottweilers - who needs a key!
I used to say - if you can get past the dogs, you can have the VCR.
My next door neighbors have a burglar alarm, outside lights and a high fence. They also have two English Mastiffs at about 180 pounds per dog. All they need are the dogs. I wish they would put up video cameras so we could see the look on the face of anyone who breaks in.