IF the rodent problem substantially impaired habitability (e.g. made it unhealthy to live there) and you failed (whether or not you tried) to correct it within a reasonable time after receiving notice of it, then the tenants may well be entitled to monetary compensation for the period of time they have lived with the condition. Such compensation generally takes the form of a rent abatement or rebate, the amount of which depends on the circumstances. For example: say the rental home was one story plus finished or semi-finished basement. Say the basement had a bad infestation which made it essentially uninhabitable for 3 months. Say the basement was 1/3 of the liveable square footage. A court might, in that situation, find you owe the tenants 1/3 of a month's rent for 3 months, which would be 1 month.