Some pest control companies offer service contracts in which structures are routinely treated for a particular pest. Contracts may be necessary in some situations such as warehouses that receive crates often infested with cockroaches. In general, routine pesticide applications in and around your home are not good unless there is a constant infestation by a pest and non-chemical methods have failed to control the pest. Service contracts for the homeowner should include periodic inspections, but pesticides should not be applied unless the pests are actually present and cannot be controlled by other means.
Generally, it is customary for termite control work to be guaranteed from one to five years. Make sure you know what the guarantee covers and determine if there is a yearly inspection charge. In addition, find out if the pest control company is responsible for structural damage if the treatment fails to control the termite infestation. The guarantee is only as reliable as the company that offers it.