Can you write in the contract to have tenant pay for pest control

[Julia Tse]

Our previous tenants left a house full of Cockroaches, we spent 2 months to fully clean it up.  The property is townhouse sharing walls with neighbors, now neighbor said they also have cockroaches.

The pest control company said that Cockroaches are in-door ones, brought by residents. The previous tenants are very mess, trashes are not taken out daily. Since we can not control how a person live, just to prevent this happening again, can we write in the contract to ask tenants to keep the place clean and if any bugs/cockroaches, tenants will be responsible to clean them?  Can we write such clauses in the contract, the property is in CA.

Thanks!