I had to laugh---- When my DD drove me to Indiana this year, we got there, drove to the grocery store the next day, and was reloading her suitcase in the car for her to come home, when the car started beeping. We could not find out what was doing it. She called the Toyota dealer and made an appt to see them the next morning. THEN we found it..... it was an alarm clock that was in the car...I had not taken it out because I had one in the cabin. Somehow, it had been bounced and the alarm was going off! LOL She called and cancelled the appt. They told her of another similar thing that had happened to someone else! Glad yours was not someting serious!!!!

Consider planting a Hornbeam tree. they are durable and long lived trees with roots that will not damage your sidewalk. Just do web searches on the American hornbeam and the European Hornbeam trees. Of the European Hornbeams, the Carpinus betulus 'Frans Fontaine' is a narrow less formal looking tree which grows tall but continues to stay narrow even after reaching maturity. The Carpinus betulus 'Fastigiata' grows into a more formal, narrow, oval to vase shaped form. Near maturity it will begin to spread wider into a more oval canopy form than the 'Frans Fontaine' Mature height is 40-50 feet. The tree does not drop litter other than leaf litter when it enters its winter dormancy. The tree grows fine in shade or sun exposure. Hornbeams do well in alkaline soils especially where the soil becomes more alkaline due to leaching from cement sidewalks and foundations. It is considered a good street tree, provides good shade, and can be very effective when planted in a group to create a screen. They have crisp, green summer foliage and smooth gray bark. They do not suffer from common insect or disease problems. They grow best in well draining soil, but will tolerate a wide range of soil conditions; even in clay soils. They are hardy down to USDA Zone 5 and do fine growing in my local 6b/7a zone.

***SIGH*** I hear you! Where I "used" to live in PA,we could go away for a week and let the door unlocked.Here...we had to put up locked gates because the freaks back the alley have teenagers that think it's ok to walk in my carport and take...my lawnmower and our tools when they need money.We learned the hard way that this isn't our small hometown....now we lock everything up.Wonder what the kids back the alley are doing for money these days? Brats! Then they come past and say"good Evening" real sweet! Grrrrr! The neighbor saw them taking my stuff ,I should have called the cops but he wasn't SURE which kid it was.There are about 5 of them back there.More on any given day. Cops are always back there.Only bad family on our street! (Of course there's only 5 houses here counting the one on the corner.)

It's a good idea and it would probably scare off an intruder, I think. I would test it though, to make sure it'll work from your bedroom to the garage. I keep my keys in the car, which is probably not smart, but it's locked into the garage which is right under our house so if the garage door goes up we know it instantly. The four dogs (big, mean and scary sounding) would let us know if anything was happening that we weren't aware of. Do you ever watch "It Takes a Thief"? It's about home protection and one of the biggest things the thieves worry about is barking dogs. They target homes that don't have any of them. So obviously, noise is a huge factor.