Why the roaches keep returning after treatment
If cockroaches keep returning after treatment, it usually means the root cause was never fixed — such as gaps in the structure, a moisture problem, or an untreated neighboring unit — and the landlord may need to do more than a single spray.
A one-time treatment rarely ends a real infestation. Roaches come back when their hiding spots, water sources, and entry points remain, or when only one apartment is treated while the rest of the building stays infested. A recurring problem usually calls for repeat professional treatments, sealing the gaps roaches travel through, and removing the moisture and food that draw them.
When a landlord keeps applying quick fixes that do not work, the ongoing infestation can remain a habitability violation. Keep a record each time you report it and each time treatment fails. If roaches keep coming back no matter what your landlord does, a free review can help you understand your options.
This is general information about California tenant rights, not legal advice. Every situation is different.