Start with one number: a mouse can fit through an opening about a quarter of an inch, roughly the width of a pencil. That is the CDC's figure, and it explains why openings matter more than almost anything else.
Where to look
The CDC's inspection list covers these:
- Where pipes enter the wall under the kitchen and bathroom sinks
- Behind and under the stove and refrigerator, where gas and water lines pass through
- Under the front door, if there is no sweep or it is worn
- Around radiator pipes coming up through the floor
- Around vents and utility line penetrations
One more is ours rather than the CDC's, because it is specific to apartment buildings: inside a utility or riser closet, where pipes pass between floors.
Photograph the opening and report it
The most useful thing you can do is photograph the opening and report it. In an apartment building, penetrations can involve plumbing, gas, electrical and fire-rated assemblies, and they are better repaired properly by building staff than packed with something from a hardware store. This is also work NYC's rules require the building to do as part of correcting a pest condition, including fitting door sweeps that reduce gaps to no more than a quarter inch. You are asking for something the code already expects.
Correcting a pest condition requires sealing holes, gaps and cracks in walls, floors, baseboards, around pipes and conduits and inside cabinets, and fitting door sweeps that reduce the gap between the door and the floor to no more than a quarter of an inch.
28 RCNY §54-04(a)Other things that help
Secure food and water. Dry goods in hard containers, trash covered, and any leak reported.
On traps and poison
If anything is set in your apartment, the CDC identifies traditional snap traps as the first trapping approach and advises against glue and live traps.
What you should not do is scatter loose rodent poison around an apartment. Beyond the risk to children and pets, an animal that dies inside a wall can leave an odour that is difficult to locate or access.
The rules above are the city's. This next part is our practice rather than a rule. Whether traps, secured bait stations, exclusion or some combination is right is a decision for the building's pest professional, who can see the pattern across the whole building rather than one unit.
What to tell your building
The opening, where it is, and what you are seeing near it. If you have reported repeatedly in writing and nothing has happened, 311 accepts apartment maintenance complaints.
Pest control in an apartment building requires treatment, repairs, access and information working together. See how the pieces fit.
Send this to your building
If other apartments have the same problem, one message to your super or managing agent does more than ten calls about one unit. Copy this and send it however you already talk to them.
Edit it before you send if you want. No sign-up, nothing collected, and we do not see who you send it to.
Where this rule comes from
Sources
- CDC — How to Seal Up to Prevent Rodents
- CDC — How to Trap Up to Remove Rodents
- NYC Health — How to Control Pests Safely: Getting rid of roaches and mice (PDF)
- 28 RCNY Chapter 54 — Indoor Allergen Hazards rules, including the §54-04(a) work practices (PDF)
- NYC Administrative Code §27-2017.8 — Integrated pest management practices
- HPD — Indoor Allergen Hazards (Mold, Mice, Roaches and Rats)
We are a pest control company working in Bronx and Brooklyn apartment buildings, and this is general information rather than advice about your apartment or your lease. Where our sources conflict with each other, we say so on the page rather than picking one quietly.