我原来的合同没有明确写,有的房客就盯着我,然后我就花了钱找pest control company做了treatment.千万不要自己做,pest control company has warranty. 房客就折腾他们去吧。我答应一次性付一笔钱,然后以后房客自己renew warranty, quarterly payment is about $75. 后来我签新的合同,一律写清楚,房客must contract with designated pest control company to have warranty.就没有什么纷争了。