Keeping Rodents Out of Your School Webinar Report
Thank you for attending the Keeping Rodents Out of Your School webinar broadcast on January 27, 2015, a part of the School IPM Webinar series hosted by EPA’s Center of Expertise for School IPM. Included here is the contact information for the presenters, webinar statistics, responses to questions and comments, and related resources.
On this page:
- Robert Corrigan, Ph.D., Rodent IPM Specialist, New York City Board of Health and Mental Hygiene
- Dr. Riegel, Ph.D., Director, of New Orleans Mosquito, Termite and Rodent Control Board
790 people from 43 states and 2 countries representing > 4.4 million students (4,433,825)
Top 5 states: CO (152), NY (75), PA (72), OR (65), FL (51)
Top EPA Regions: Region 8 (165), Region 2 (120), Region 10 (102)
567 schools/districts/child care centers
431 - school facility, buildings and grounds managers
136 - child care centers
63 - pest management professionals
75 - departments of Health
70 – others. including government (46)
13 - Tribes and Indian Health Service
Outreach - “How did you learn about the webinar?
- 69% from an EPA generated email or website
- 14% other source including
- 7% from an educational services or university contact
- 7% from school/district administrator
- 3% from a pest management association contact
Registrant IPM Status
- Their school has a pesticide safety and IPM plan or policy: Yes (63%), No (9%), Not applicable (20%)
- 58 were unsure and wanted more information
- Their school has an IPM coordinator: Yes (59%), No (13%), Don’t know (8%), Not Applicable (21%)
- 46% of those who registered attended representing 3+ million children (3,014,549)
Attendance was lower than anticipated due to a blizzard in the northeastern US that closed many schools.
- Top 5 states: CO (57), OR (39), NY (33), PA (32), OH (25)
- 205 schools/districts
- 42 childcare centers
- 39 departments of health
- 29 pest management professionals
- 9 Tribes and Indian Health Service (FL, MN, MO, MT, NM, WA)
The questions below were posed by the webinar participants. The responses may have been refined by the presenters following the webinar for clarification or to include additional resources.
- Rodents have bladders but it seems like they cannot control their urination. True or False?
(Dr. Corrigan) - It may be they don't control their urine deposits; and as a result it leads to successful colony communication. Whether or not they can't control their urination, I'm not sure. A physiologist familiar with rodents specifically would have to answer that. If I had to guess, I would think they have little need to control it; but perhaps they might in areas where there could be predators lurking and sniffing for them.
- What are the health consequences from breathing in house mouse droppings dusty areas?
(Dr. Corrigan) - It would be a case by case basis. If the droppings' dust contained allergens, or some type of pathogenic microbe, then there could be potential health consequences; perhaps even some being serious. However, if the dust is absent of anything pathogenic, then nothing more than breathing in dust and the consequences as such; could be very minor to nil.
- You say that mice like to live in the boxes in the back that are normally untouched. Would rotating boxes help this problem?
(Dr. Corrigan) - Absolutely. It’s plain smart organizational sanitation.
Can you talk more about the products that are best for exclusion, such as what we should look for in a sealant?(Drs. Corrigan and Riegel): A few examples (but not all-inclusive or exclusive of any others):
Xcluder mesh in the various formulations
NP-1 (by Sonnebaum Corp)
Rustoleum Industrial Grade Sealant and Caulk
Mixing quick drying professional level quality gun foam (e.g., Todol foams) enmeshed with Xcluder mesh
There are a variety of off the shelf products such as kick plates, concrete patch, hardware cloth, etc. that are inexpensive and readily available. The key for using these products is to use items that are durable, and a Purdue University extension bulletin discusses the properties of sealants and other exclusion materials.
- What is the difference in the travel patterns of mice and rats?
(Dr. Corrigan) - Both species try to remain hidden; follow shadows and get behind objects as much as possible while they travel.
Mice have home ranges indoors of about 10-30 feet; but can be more or less depending. Norway rats: home range indoors about 25-100 feet depending on food and nest orientation.
- Are the black bait boxes used outside around the perimeter of schools used mainly for rodent monitoring (to determine population levels and therefore threats) or for rodent control? Are they effective in controlling rodents in areas where their numbers are high? Do they attract rodents to the facility?
(Dr. Corrigan) - Around schools, these boxes can be used mostly for monitoring and occasional as need be, trapping. Non-toxic monitoring baits are available and are excellent for school IPM programs. Baits might be warranted for very unique and tightly controlled situations should a school be invaded from field rodents, etc.
- Any new data on secondary poisonings of non-target animals from rodenticides?
(Dr. Corrigan) - In some areas, hawks, owls and various small mammal predators are testing positive in necropsies to the second generation anti-coagulant rodenticides. In some cities like New York, hawks and owls have definitely succumbed to the rodent baits when they consume poisoned rats and mice. Some portions of the world are beginning to raise significant concern over this side-effect, and are considering outright bans on the second generation anticoagulants.
- I have had good luck with Pest Specific Foams sandwiched with hardware cloth. Any more suggestions?
(Dr. Corrigan) - I have had success with Todol Professional Foam in a sandwich technique with the excluder stainless steel mesh for denying rats in sidewalks and walls.
- How often does Dr. Corrigan encounter situations with documented biting of building residents by mouse mites? Frequently? Uncommon? Very rarely?
(Dr. Corrigan) - Among documented cases, it is rare. But it is being hypothesized that cases are being overlooked or misdiagnosed. Suffice to say, if there is a large/rat mouse infestation, pest professionals should trap mice on glue traps and confirm whether or not the mouse mite (or the tropical rat mite) are also present. If so, they should treat for them. If not, nothing additional beyond the rodent remediation is necessary.
- What is the best bait to put on a snap trap for a house mouse and Norway rat?
(Drs. Corrigan and Riegel) - There is no one best bait. Here is what tends to work:
match what they have been feeding on within or around the infestation site
grain seeds or oatmeal flakes or wheat
moist foods ( cucumbers, tomatoes, apples), especially during hot dry periods
Slim Jim pieces
bacon grease and/or bacon bits
bread with soft dog food
- Could a field mouse bring ticks into the building?
(Dr. Corrigan) - I don’t see why not. But they not likely to bring in many. I would consider it an incidental occurrence.
- Are schools legally responsible if they are aware of this type of problem and fail to act?
Dr. Corrigan) - While I'm not a lawyer, I would have to guess, yes. Wild mammals entering or being delivered into a school could perhaps be labeled an "act of God." However, failing to take the proper remedial procedures ASAP, and also failure to properly profile whether or not there is an actual health impact to the building occupants from allergens, fires, rodent bites, ectoparasite bites, seems negligent. Would a school be negligent if it failed to eliminate a known yellow jacket nest on the playground? Or bedbugs? Or identified mosquito breeding water on the school grounds?
- If we find evidence of mice, what precautions should we take to remove the droppings, etc? Gloves and mask? What are the risks of hantavirus?
(Dr. Corrigan) - It is best to consult the disease experts at the Centers for Disease Control. The CDC has specific detailed instructions as to how to handle such scenarios and what precautions and equipment are necessary for minor or severe infestations.
- Does IPM cover microbial pests like flu and MRSA?
(Dr. Corrigan) - No. Microbes are not considered pests in the realistic sense of the word. But because IPM requires detailed cleaning, microbial pathogens that are subject to risk via contact (vs. inhalation) are apt to be removed and thereby pose a lessor risk. CDC guidance on sanitation measures for mouse evidence and nesting materials relies on the use of bleach. The guidance is primarily interested in disease prevention.
Can you recommend a method for cleaning nests, urine and feces that using reduced risk cleaning materials that will limit exposure to asthma triggers, allergens and dust during clean up?
Many times cleaning will disturb dust and distribute allergens into the air.
(Dr. Corrigan): See the answer to Question 13.
Are there any special measurements or techniques we should use to clean up rat/mouse evidence?
(Dr. Corrigan) - See the answer to Question 13.
How do we fix gaping holes in doors?
(Dr. Riegel): There are many types of holes and sizes. Each will be unique and needs to be evaluated to close so that the patch is stable and resistant gnawing rodents.
I have heater vents in my school. Are there any tricks to keep the mice out of the heater vents?
Dr. Riegel): The best way to prevent mice from entering the heater vents is to eliminate the infestation. Mice are prone to loosing body heat quickly so they need to eat frequently and/or stay in warm areas. The heater vents will provide that warm area for the mice. Hardware cloth is an excellent material to use to screen the vents. You need to make sure that the openings are small enough to keep the rodents out and not to impede the airflow. ¼ in is recommended for mice but you may select a smaller opening such as 1/8. Galvanized stainless steel is commonly used, just be sure to use a low enough gauge so that the rodents cannot gnaw or push through the metal. Depending on the heating system, you will likely have to inspect the ductwork to make sure the mice have not gnawed through the lines. The insulation around the ductwork is an attractive nesting material. If the mice are or have been in the duct work, it is important to have it inspected/cleaned so that potential contaminated air (viruses, mouse protein) is not being distributed throughout your building. The Centers for Disease Control and Prevention have the following statement on their website.
Air ducts (heating and cooling ventilation systems)
When there is evidence that rodents have access to heating and cooling ventilation systems, it is best to contact a professional rodent exterminating service to remove them. Companies specializing in duct cleaning are familiar with the particular problems and risks associated with rodent infestation in ventilation systems. For more specific information on eliminating rodent infestations in heating and cooling ventilation systems and the companies that perform this service, refer to the Environmental Protection Agency's website.
If roof rats don't eat peanut butter on traps, does that mean they are gone?
(Dr. Riegel) - There are a variety of traps that can be used. Some of these are a live catch traps, glue board (used primarily for monitoring), and snaps traps.
My suggestion to determine if rodents are gone from an area, structure, etc., is to use a variety of different monitoring devices and provide several food options in the stations or traps. For example, bait stations with bioluminescent baits (with no active ingredients) and glue boards can be used. However, the most important thing to do is carefully inspects on a regular bases for signs of rodents. If the structure was previously infested and rodent droppings were present, be sure to remove the droppings and watch for new activity.
Food choice and competition: Peanut butter is commonly used to bait traps. It is a good choice, however, the rodent may have other preferences so generally a few choices should be offered in order to increase the likelihood the rodent will “hit” the traps. It may be that the rodent does not select peanut butter and does not touch the traps. There may also be food competition and the rodent may not be interested in the bait on the traps.
The rodent(s) may have had a bad experience with the trap selected. If a whisker (vibrissae) was lost on a trap or had a body part became stuck in a trap (glue board), the rodent can learn to avoid that device. In addition, if traps are placed in location, rodents can be hesitant to approach the devices and can avoid them all together (neophobic).
How is that 100 year-old school doing now Dr. Riegel?
(Dr. Riegel) - The school is currently in a two-year, $30 million renovation which began in June of 2014. The school is a historically important so the Recovery School District chose to fully renovate instead of demolishing the building.
Why does caulk work but expandable foam doesn't? Can you elaborate?
(Dr. Riegel) - A sealant is an elastomeric material that allows for 25-50% movement. Sealant is used to fill gaps, to keep water and air at bay, to allow for expansion and contraction of building materials, and to enhance aesthetics. Silicone and polyurethane are two popular types of sealant. Despite their common purpose, there are a few major differences.
Is it the 'norm' for students, teachers or other staff to see mice in schools that are infested?
(Dr. Riegel) - Each school is different and each will have its challenges. I do not believe it is, or should be the "norm" for school staff to see mice. Mice are the most common commensal rodent is buildings. Most people have had and a run in with a mouse at home or at the workplace. Schools will be no exceptions. Despite the best IPM plans, every building is incredibly difficult to close completely. Repairs are made, doors are left open, wear and tear of the building occur. It is important to have a monitoring program in place to detect mouse infestations early so that they can be targeted while you have an occasional invader instead of a full blown infestation.
What is the best alternative to expansion foam for sealing openings that may allow pest intrusion?(Drs. Corrigan and Riegel) - A few examples (but not all inclusive or exclusive of any others):
Xcluder mesh (various formulations)
Rustoleum Industrial Grade Sealant and Caulk
There are a variety of off-the-shelf products such as kick plates, concrete patch, hardware cloth, etc. that are inexpensive and readily available. The key for using these products is to use items that are durable and do not rust. These materials allow for customization of patches to seal openings. Purdue University provides is an excellent bulletin that discusses the properties of sealants and other exclusion materials(2 pp, 8 K, About PDF). Exit
We welcome your participation in our upcoming webinars and ask you to encourage your peers to attend. These presentations are geared specifically to school and school district facility managers, buildings and grounds managers and staff, childcare facility managers, and school IPM practitioners. School nurses, school administrators, health officials, and pest management professionals are welcome to attend.