Successful long-term rat control is not simple; a continuing commitment to whatever solutions are adopted is required. Within a population, some rats will be easy to control, some difficult. Complete control is often not possible in old barns and similar structures. Rat populations may also be a consequence of community-wide activities over which you have little control—improper garbage disposal, building demolition, and poorly maintained bird-feeding stations.
Total cost may run anywhere from $100 to $1200 depending on the size of the concerned property and severity of infestation.