Tenants wants to deduct rent in California

[Jacky Johnson]

Today my tenant sent me a notice via text that my rental property has a sewage leak under the bedrooms and asked me to check it out. He also mentioned rats are living under the house biting away wood and pipes and he called a pest control company to trap, poison, and got rid of the rats and cost him $465 and he paid. He wants to deduct this amount from next month's rent and asked me to send him my email for the invoice. How should I handle this? Thanks!