Once the exterminator has arrived, explain the situation, hand over any records of the issue you have (such as a diary) and then let them talk you through what the suggestions are. Most exterminators these days offer humane and conventional methods when it comes to dealing with issues be sure to explain to them exactly what it is you are looking for. The exterminator will be able to tell you exactly what the plan is and exactly how much it will cost along with estimated time to complete the work. Remember, make the exterminator feel welcome, its hard work.