Legal Question in Landlord & Tenant Law in California

Nope. If the property is delivered free of vermin, and the tenants are in control of the areas that become infested, it is the tenants responsibility. I had tenants who tried to hold me responsible for rats that moved into the basement and kitchen (nesting under the range). Considering they left the back door open for their dog to go in and out, AND left food in the back pantry just inside the open back door, AND failed to keep the ivy in the back yard trimmed back, they found out the hard way who is responsible for vermin caused by the tenants choices.