Burglar alarm

A burglar alarm is a wall-mounted object that can be bought in buy mode to automatically alert the police that a burglar is on the property.

In all games, it is impossible to enter build or buy mode after a burglar enters the lot. It is important that players properly secure the lot with the burglar alarm before a burglar arrives.

The Sims
In The Sims, a burglar alarm will cover an entire room when placed indoors. If placed on an outside wall, it will cover a 5-tile radius.

An easy way to make a house burglar-proof is to build a single wall on both sides of the lot and put a burglar alarm on each; when a burglar enters the lot, the alarms will be set off instantly, resulting in the police being summoned immediately, often before the burglar can even enter the house.

The Sims 2
In The Sims 2, a burglar alarm will cover the entire room it is placed in. Burglar alarms cannot be placed outdoors, unless the moveobjects cheat is used. Each room with a door to the outdoors should have an alarm. If cheats are used to place a burglar alarm outdoors, it will cover the entire outside area, obstructed only by outdoor fences.

It is found under "Electronics -> Small Electronics" catalog.

The Sims 3
In The Sims 3, burglar alarms can be placed on any wall of a residential lot, inside or outside. The alarm will sound if a burglar enters through the front door or close proximity to the alarm when placed outside. It also costs more than the previous generations. When the alarm is activated by the presence of a burglar, the burglar will be stunned by the alarm until the police arrive.

If a burglar alarm is put on the outside of a house, it will go off as soon as the burglar is on the lot.