Why one-unit treatment rarely works
Yes. Bed bugs spread easily between apartments, traveling through wall gaps, electrical outlets, baseboards, and shared spaces. That is why treating only one unit often fails and building-wide treatment is usually needed.
Once bed bugs are in a building, they move from unit to unit searching for hosts, especially when a treated apartment sits next to an untreated one. This is a major reason the landlord is generally responsible for treatment — a single tenant cannot control what happens in neighboring units or inside shared walls.
If your landlord treats only your apartment while ignoring the source next door, the infestation is likely to return no matter how carefully you prepare. Effective control usually means the landlord inspects and treats the surrounding units too. If bed bugs keep coming back because the building is not being treated as a whole, a free review can help you understand what the landlord should be doing.
This is general information about California tenant rights, not legal advice. Every situation is different.