How does the owner explain that there are rats in the unit?

Whether there is responsibility, according to the property management contract to decide.

Usually, the service content of property management contract includes environmental disinfection, pest control and so on. The definition of responsibility is not based on whether there are rats, but on whether the rodent control work agreed in the contract is carried out according to the frequency. As long as the frequency is reached.

Off-topic, the prevention and control of four pests, usually including rodent control, is one of the work contents of neighborhood committees, and most property companies cooperate.