Can my tenant withhold rent for civil code violation?

[Celeste Cuervo]

My last tenant owes me for two weeks rent. He claims that I did not provide a safe environment in violation of California Civil Code re. the free of vermin wording.

I dropped off my cat at the house without a flea collar because the cost of a collar was very expensive. I then left on a trip.

He states he awoke to a bed full of fleas. He did not want to use a bomb because he said they are toxic and ineffective. He used mechanical controls and said they were gone after 3 weeks.

I feel that he should have used the bomb and been done with it. If I take him to court can he prove this ever took place? Is he not still liable for the rent?