How to Tell If Someone’s Been Sneaking Into Your Bedroom

Perhaps you have untrustworthy roommates and want proof that they’re sneaking into your room when you’re not home. Or you’re staying in a sketchy motel and you don’t trust the locks. Or maybe your kid wants to have fun sibling-proofing their room. Whatever your reasons, you’re in the market for an extra layer of DIY surveillance.

For more serious security, you should probably look into installing a real security camera. (Additionally, it helps to know the facts about preventing home burglary). In the meantime, let’s dive into some of the crafty tricks you can use to determine whether someone is sneaking into your room when you’re not there.

First we’ll consider some low-tech solutions for tapping into your inner spy, then touch upon higher-tech solutions like motion activated cameras, which might be necessary for your situation.

Use a piece of hair, James Bond-style

This trick comes from Dr. No (1962), which also happens to be the movie where 007 delivers the iconic “Bond...James Bond” line for the first time. Here’s how this hack works:

Attach a thin, barely visible hair or piece of thread in front of your door, such that it crosses the crack between the door and wall. Bond uses spit to get the hair to stick, but a small piece of clear tape is more reliable (although far less suave). The thread will tear or fall down if anyone has opened the door in your absence.

Another approach is to tape the piece of thread on both sides of your door. When the door is opened, the thread will pull out from underneath one side of the tape.

Wedge a small piece of paper into the door

From inside your room, fold a small slip of paper and wedge it into the doorframe. Check the outside so that you can see a small piece poking out from the other side of the door—take a picture of exactly what it looks like. When someone opens the door, the piece of paper will fall out of the hinge and onto the floor. If you get home and see the paper is no longer peeking out from the outside, there’s a chance someone opened your door while your were gone. If the culprit tried to wedge the paper back in before they left, compare the placement to your before photo.

Alternatively, you could stick a small strip of clear tape with one end touching the bottom of your door and the other taped to the floor. If it’s altered or gone when you return, the door could have been opened.

Set a booby trap

This one is messy, but the most obvious. Place a glass of water on the ground so that if the door swings open, the water will spill. Ideally, you have a rug or mat that will take longer to dry, so the intruder can’t just clean up the mess and reset the trap before you return. Just make sure you don’t swing open your door and fall victim to your own trap!

Side note: Is anyone else weirdly in the mood to watch Home Alone right now?

Leave a treat

If you have a mat or rug, place a cookie, cracker, or some other crunchy snack under there. If someone unwittingly steps on it, sure, you’ll have a mess to clean up—but more importantly, you’ll have evidence that something is afoot.

Break out the baby power

Sprinkle a thin line of baby powder right behind your door (or in whichever direction it opens). If the line is broken either by the door swinging open or by someone else’s footsteps, you’ll know. The trick with this one is to set the line far enough back that you won’t accidentally break it yourself, and to eliminate the chances a breeze or pets will disturb the powder instead.

Consider investing in higher-tech solutions

All the tricks above are crafty, but leave plenty of room for error. If you’re seriously anxious about someone breaking into your space, it might be worth investing in gadgets. These don’t have to break the bank; many motion sensors will run you about $20.

Higher-tech solutions include installing a noise-recording app on a smartphone or investing in a security camera. The benefit of a camera is, of course, that you can actually see who is doing the intruding.

Look into a wireless or battery-operated security camera; not only are wires a hassle, but they’re easy to disable if you’re dealing with an intruder who means business. If you can’t afford a proper security camera, shop around for hidden webcams and baby monitors.

Stay safe

If you suspect someone is breaking into your room, take precautions not just to catch the perpetrator, but to keep yourself safe. Change your locks and consider investing in a high-quality mechanical lock (not electronic).

One last tip: To give yourself peace of mind (or proof of trespassing), take before and after pictures of your room every time you come and go. Finally, if you’re ready to bust out your credit card, here are the best home security systems to look into this year.