Rat extermination is not as simple a process as roach or ant control is. For roaches and ants you can simply spray pesticide and they will be controlled. But it is not so in the case of rats. For rats you will need to adopt a completely diverse approach. Unlike roaches and ants, rats can smell the various dangers around them. They will use every tactic to avoid the various pesticides and sprays, to stay alive. To effectively carry out the rat extermination, you will need to use various do it yourself pest control methods.
When you decide to handle the rat control problem yourself, the first thing that you should check out is their place of residence. After locating their living area you should find their path into your home. That is how they enter your home. They can come through the roof, some holes in the basements or doors. Try to block all the incoming routes for the rats. Normally the rats look to live in a dark places where there is no noise. So you can look into your store rooms for balls of fur. Keep track of all the dark nooks in your home. Also take notice of their droppings that rats will have left on the way to their holes.