[Vertebrate Pests] Apartment Mouse IPM:

Complaint Response vs. Infestation Management

The house mouse is a ubiquitous pest of apartment buildings the world over. There are several reasons for this. First, apartment buildings are relatively easy for mice to gain entry via doors, foundations, utility openings and open windows. Moreover, because of their small size, mice are periodically shipped into apartments as stowaways in new tenant moving boxes and furniture, as well as the ongoing supplies and deliveries of the residents.

Second, apartment buildings are structurally divided up into individual units that may consist of up to hundreds of tenants. Each apartment contains warm kitchens, food closets and pantries and multiples of nooks and crannies — all ideal for mouse proliferation.

Third, within every apartment building, there will be apartments located among the different floors that are cluttered and untidy. These apartments can serve as mouse reservoirs for the entire building.

Fourth, apartment buildings are connected from top to bottom and from side to side via various utility pipes and wirings, as well as via different building support elements. These linear connections facilitate mice spreading relative quickly from one apartment to another. In fact, because one person’s ceiling is another person’s floor, mice readily forage among two or more different apartments on any given feeding foray.

And finally, most complexes contain numerous apartments with pet owners, which are generally conducive to rodent problems.

Servicing Complaints versus infestations. For new and/or minor infestations, gaining control of the mice is not difficult or complex. If the infestation is contained to only a couple of apartments, the mice usually can be eliminated via control efforts within those apartments directly (although a quality service also inspects those apartments all around the effected apartments to prevent spread of the new infestations).

But when mouse infestations become widespread and entrenched in apartment buildings, a coordinated effort between the landlord, the tenants, and the pest professional will be essential.  A routine monthly service of a technician “hitting the complaint apartments” with some baits or sticky traps will not impact the infestation at the building level in the long run.  For established infestations, holistic approaches are needed.  In other words, there is a big difference between servicing the complaints and servicing the infestation.

Partnership Is Essential. If mouse control in apartment buildings is to be successful, there needs to be a team approach in place. What follows is a summary of everyone’s responsibilities.

Landlords and Superintendents. Contrary to what most apartment tenants believe, the greatest share of preventing and controlling mice in apartment buildings actually lies more with the building management than with contracted pest professionals. Sanitation and pest proofing, for example, are essential to avoid the all too common “harvesting” of mice. Of course, this is not news to pest professionals. Yet often apartment managers mistakenly think their monthly pest service will “take care of” the building’s pest issues. And for convenience sake, this is what can be relayed to any complaining tenant (e.g., “You saw a mouse? Okay, I’ll tell the pest control technician when he/she comes.”).

Building property owners and managers have a three-fold responsibility in the partnership: pest proofing, sanitation and complaint recording.

1. Pest Proofing Apartment Buildings. Here are some tips for pest proofing apartment buildings:

  • All doors to the apartment building must be rodent-proofed and all crevices below doors sealed down to ¼ inch (8 millimeters — this is the equivalent of a No. 2 pencil lying flat on its side).
  •  All penetration lines and any structural wall, floor and ceiling gaps in basements, utility rooms, (e.g., laundry rooms, compactor rooms, storage areas etc.), must be properly sealed.
  • Within each apartment, all doors to the apartments should be mouse proofed to prevent mice from entering apartments via the hallway, as well as to prevent mice from infested apartments spreading to those across or down the hall.
  • All utility lines where pipes enter walls, floors or ceilings within apartments should be sealed with high-quality sealants and/or covered with escutcheon plates (containing a bead of sealant to keep them in place). Simply “plugging” holes with steel wool, copper mesh or wrapping duct tape around holes does not provide long-term pest proofing. (For more information on pest proofing, refer to the Vertebrate Pests column “Pest Proofing Small Holes” in the June 2005 issue of PCT).  There are four lines in particular that need attention to seal off the routes of apartment house mice:
    • Kitchen plumbing lines beneath the cabinet
    • Bathroom plumbing lines beneath the cabinet
    • Gas lines penetrating the floor for the stove
    • Floor heating radiator lines from below

2. Sanitation. If the utility rooms and basement areas are not kept clean and rodent proofed, these areas (in addition to the untidy apartments) can serve as mouse reservoirs for the entire building.

These areas must be cleaned regularly (daily or several times weekly) to prevent the ground floor from becoming “mouse central.” Laundry and compactor rooms are prone to people leaving snacks while they do their laundry. Mice benefitting from these foods often will nest below washers and dryers. In the compactor room, it is common for mice to nest within the dead end voids of the compactor chute at the base, or they will nest within the concrete hollow block up and down the length of the compactor chute and access the chute via any gaps its seams.

3. Pest Sighting Log and Plot. Most building supers or managers maintain tenant complaint logs to address pest complaints. In addition to the log, it is helpful to maintain a pest sighting plot. The plot need not be anything more than a simple building plan. For every complaint, a mark is made in the appropriate apartment, floor or wing. In this way, complaints can be visually analyzed as to whether or not mice are spreading along one wing, or one floor and so forth. This information can assist the pest professional in surrounding the infestation “source” and working inward. Without such complaint plots, the pest service can deteriorate to simply “putting out fires,” and this approach can go on for years without ever actually reducing the building’s infestation.

The Contracted Professional. To control mice at the infestation level vs. the complaint level requires service beyond working off of a complaint list and installing traps and/or baits into the complaint apartments. As stressed earlier, those apartments within structural proximity (above, below, flanking) to the problem apartments must be considered. It is the job of the contracted pest professional to not only service complaints, but to be aware of possible sources of the infestation, possible building reservoirs and the likely entry /travel points of the rodents using the building. To not address the building’s sources can result in future complaints (i.e., profit-eating callbacks) as well as allowing the infestation to possibly worsen “under the watch” of the current pest control contract.

For trapping and baiting programs, thoroughness is the key. Special attention should be paid to:

  • Those apartments that have had repeated mouse complaints.
  •  All utility rooms (laundry, furnace, storage, community centers, compactor rooms, refuse storage, etc.) must be kept on “high-alert” status.
  • For control efforts, combinations of the use of glue traps, snap traps and baits installed throughout the apartment complex are most effective. Simply placing out a few glue traps or baits in the basement, or in only those apartments with complaints will do little to eliminate any established infestations.
  • If baits are used, they must never be accessible to children or pets at any time. Block baits installed in mouse-size tamper-resistant bait stations are the preferred choice of baiting efforts. “Packet-style baits” should never be tossed behind appliances within apartments or within the utility rooms and abandoned. Ideally, mouse bait stations should not be visible to children or pets (mice are most active in shadowy, out-of-sight areas anyway).
  •  In problem rooms or areas, it may be essential that the mice are infesting ceiling spaces and these will need to be checked.

Again, the goal is to eliminate the building’s mouse population not capture a few mice here and there with each service visit.

The Tenant’s Role. Well, what can be said here that hasn’t been stated a “gazillion” times in every university fact sheet, every technical magazine, every lecture ever given on the relationship between good housekeeping and controlling pests? Pest professionals can do little to eliminate mice if they have abundant amounts of clutter and can readily feed from untidy hard-to-reach floor spaces, closets and cabinets. Here are some issues to discuss with tenants:

  • Clutter and mice (and all other apartment pests) go hand-in-hand. Tenants experiencing any pest issues must be encouraged (via fact sheets, Web sites, etc.) to minimize clutter and maximize cleanliness.
  • A mouse only needs small crumbs of food each night to survive. Unfortunately, most of us in our homes and apartments only sweep and mop those areas we can easily reach.  To impact mice (and cockroaches and ants), refrigerators and stoves MUST be pulled out and the nooks and crannies beneath and behind thoroughly cleaned.  Bases of cabinets vacuumed of all old spills (grains of rice, beans, flour, etc.).
  • In infested apartments, pet foods must never be left out overnight.

Summary. Mouse infestations inside apartment buildings often are more complex than property owners, building superintendents and even many pest professionals realize. There is a difference in a pest management contract that provides a service to address the apartment building’s complaints vs. one that addresses the building’s infestation.

Most apartment property managers probably assume their contract’s goal is, in fact, to reduce or eliminate the infestation, not to simply prevent the infestation from “getting worse than its current level.” But to meet the goal of infestation elimination, the three-way partnership of owner, tenant and pest professional (beginning with sales) working together is essential. If any of the partners fails to participate, the mice may be “controlled” (or the perception they are) via the service-the-complaints model. But it’s a fair bet, that unbeknownst to busy tenants and supers, day by day, apartment mouse infestations, are slowly increasing. Eventually, the pest professional is blamed, fired and a “new and better” pest company is “tried.”

If the new and better company is hired “cheap” (i.e., paid to service only the complaints), the cycle repeats over and over and over.

The author is president of RMC Consulting, Richmond, Ind. and can be reached via e-mail at rcorrigan@giemedia.com.

July 2009
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