If you get home and discover that you locked yourself out of the house, you may go around and check all your windows to see if you left one unlocked so that you can get into the house. The problem is that it isn't always possible for you to do that. What you need to do when you can't get into your house is to call a locksmith. They can get you into your house without you having to break in, an act that could cause all kinds of problems. When it comes to getting into your house, there are a number of tools and techniques that the locksmith can use, both non-destructive and destructive.
A bump key is basically a key blank that has some modifications done to it. The modifications aren't going to be precise to your particular lock, because the pins and barrels in each lock are different, but the key should be one that is the same brand as your lock. Locksmiths may have several bump keys, depending on the various brands of locks and the different kinds of locks. The bump key gets put into the lock, and the locksmith will basically bump, wiggle, and jiggle the key in the lock. The goal is to move the pins and barrels in the lock so that they move into the open position.
These are probably the most familiar tools to everyone, and that's for a good reason: they've been used for many years. There are several kinds of lock picking tools that people use to open a lock, but generally, the locksmith will only use two. One tool will help move all the pins and barrels around, and the other will hold things out of the way so that the locksmith can get to work. Picking a lock can take up to several minutes, depending on what kind of lock you have on your door. A simple cylinder lock on your doorknob is going to take a lot less time than a security deadbolt would take to pick.
If you get home and find out that you are locked out, then you need to call a locksmith who handles lockout services. They will have a variety of tools and techniques that they can use to get you back into your house as quickly as possible.
For more information on locksmith services, including what they might do in the case of a lockout, contact a local locksmith.