You cant always make a room intruder - proof, but its easy to be aware of unwanted guests...
Often a locked door isnt enough to stop a sneaky intruder from breaking into a room. So its vital to known when your security has been breached. If you prepare property before you leave, the clues should be there when you return!
Look at the books - It helps to have a ordered mind to catch a snooper. Arrange a pile of books or cds in alphabetical order along your shelf. If they"re out of order the next time you check, its an obvious sign that someone is tempering with them.
Split Hairs - 007 used this trick on the dr.no mission. Lick your fingers and smooth hair over the gap between two drawers or cupboared doors. If hair is broken or missing when you return, someones been inside.
Sticky fingers - Rest a piece of glossy paper or some clear cellophane over any importment documents that you dont want anyone to read. The, leave a paperweight smeared with cooking oil on top. The intruder will need to pick up the paperweight first and will leave greasy fingerprints on the glossy paper surface.