It really depends. One tenant could have an ant problem because another adjacent tenant is attracting them, which the landlord needs to address. If the structure has decaying wood, that can attract carpenter ants which is a landlord issue. Some ants like humid environments, so a poorly ventilated structure (like one with mold) could be the cause–also the landlord’s problem.
It reminds me vaguely of Operation Trojan Shield, except with explosions.