A window alarm makes for an excellent deterrent at one of the most vulnerable spots in any home. Window alarms vary in their construction and operation, but most function via the same magnet-sensor setup that characterizes door alarms. Separate the magnet from its spring-loaded latch in the adjoining compartment, and the whole neighborhood will know.

Other window alarms use embedded sensors that can detect even slight nudges and bumps as well as breaks in the glass. This too triggers a blaring siren that can awaken an entire neighborhood. But since you and your family are likely to nudge, scrape, or brush your windows from time to time, you'll want to be careful not to purchase a system that's too sensitive. After all, an alarm is meant to ward off intruders, not residents.

The Simplicity of Window Alarms

One of the biggest selling points of window alarms is their ease of installation. While an extensive home security system may require the help of techs with electrical degrees and fancy tools, a window alarm sticks to your pane with the help of a simple adhesive strip. It's strong enough to keep the sensor bonded to the window, even after repeated slidings.

What's more, you can often find window entry alarms for as little as 20 or 30 dollars. Slightly more expensive models may emit higher-decibel signals, but the more affordable variety is still more than adequate for scaring off burglars. It's important to remember, however, that once a window alarm has been breached, there's usually no built-in emergency call, unless of course your security company is the one installing these devices.