It is a common misconception that trapping pests is a solution for eradicating pests in an area. While traps can catch pests and decrease total numbers, they are actually a tool to help identify your pests as well as the source of the pest problem. Even with vertebrate pests, while you may remove the animal(s) in question from your space, your problem includes where and how it got there.
Details on trapping are in the Monitoring section of the website.