Tips for Managing Pests

Wildlife is an important part of the natural environment and is a reality in almost any outdoor setting. Getting accustomed to the presence of animals of all kinds is a key aspect to adjusting to class outside. However, in some circumstances certain species may become a nuisance and detract from the experience for students and staff, or pose a risk to health and outdoor comfort. This article offers solutions to common pest problems within the context of creating outdoor learning areas at schools. Additional resources are provided at the end.

Animals such as mosquitoes, rodents, and ticks can be a nuisance but need not deter teachers and students from using their outdoor spaces for productive instruction. When faced with pest problems, the best solution is to follow integrated pest management strategies. Integrated pest management (IPM) is an approach to pest control that focuses on prevention, implements cultural/maintenance and physical/mechanical tactics to reduce pest populations, and minimizes pesticide use. In many states, schools are required to develop an IPM plan, although some may not address the specific needs of outdoor learning spaces.

Identifying Existing Pest Problems

Various outdoor infrastructure may hold standing water, which could present pest-related issues.

There are several methods for monitoring pests, and many are specific to each pest type. Additionally, since pest activity varies from season to season, it is necessary to develop a plan that addresses potential pests for the entire academic year. The IPM plan for your school may be a helpful resource during the planning process. Another valuable resource is your staff. Many teachers or custodians may already know which pests are causing problems in your area. Finally, your local county extension agent can inform you about relevant pests in your region.

Pest Recommendations

Mosquitos

Mosquitoes are some of the most medically significant pests in the world because of the wide variety of diseases they vector, including West Nile virus, malaria, dengue fever, and others. Additionally, mosquitoes can become an intolerable nuisance during certain times of the year.

Mosquitoes rely on stagnant water in the immature stages of their life cycle, so the most effective control measure is eliminating stagnant water sources that last for 4 to 7 days. Places to look for stagnant water include rainwater catchment tanks, puddles, gutters and downspouts, tree cavities, plant pots, artificial containers, bird baths, and even abandoned tires. If removing the water source is not possible, prevent adult mosquitoes from accessing it by installing a tight mesh screen over the opening. In areas near wetlands or marshy areas, local municipal support may be needed to prevent mosquitoes from proliferating.

A fairly simple way to reduce the suitability of school campuses for adult mosquitoes is active grounds maintenance. For example, mowing tall grass and clearing brush in shady areas eliminates the habitat in which adult mosquitoes tend to rest during inactive periods.

Personal protection is another important measure to take when dealing with mosquitoes. Light-colored clothing that provides ample coverage can protect individuals from bites (Whelan, 2020). Chemical repellents such as DEET or Picaridin provide long-term protection and are regulated by the EPA. Most natural repellants, such as citronella, eucalyptus, and tea tree oil, are not regulated. Whatever chemical repellents you consider asking students to use, be aware of their risks and of state regulations regarding application. Generally, repellents should not be applied to students by school staff.

Another effective protection measure is the use of mosquito nets. Netting is highly versatile and easy to use. For instance, nets can be affixed around large open-sided tents (see Shade and Shelter), suspended from tree branches, or fashioned into individual netted cubes.

Other Swarming or Biting Flies

In many temperate regions, biting midges (i.e., no-see-ums), black flies, and eye gnats constitute an extreme annoyance for people outdoors. While these types of biting gnats do not vector diseases in the United States, their bites can sometimes cause severe localized allergic reactions. Because they breed in moist soil or rivers, chemical control is ineffective in the long term. The best methods for control include providing a physical barrier (e.g., mesh netting, long sleeves) or using chemical repellents. Thankfully, these flies are most active from May through September and are not problematic year-round.

Rodents

Rodents such as mice, rats, chipmunks, and squirrels can become pests in an outdoor classroom setting. Rodents are an important host for multiple species of ticks and may also transmit pathogens. A cost-effective measure for controlling rodents outdoors is to remove their habitat. Remove wood and brush piles, and seal any holes in structures that are larger than a dime (for mice) or a quarter (for rats). Eliminate potential food sources, including bird feeders, and be sure that trash is securely stored.

Spiders

Spiders are more likely to cause fear and disruption in an outdoor classroom rather than pose actual danger. Spiders are not aggressive and will generally only bite when threatened. However, black widow and brown recluse spiders are medically significant and should be managed in areas where they are prevalent.

The best method for spider control is to eliminate or manage the places they live. In an outdoor classroom setting, widows and recluse spiders may be found in crevices, under stumps and logs, or in old storage closets and boxes. Care should be taken when working around such spaces. Look before reaching, keep spaces free of clutter, and remove webs with brushes or brooms in eaves or overhangs as needed.

Harvestmen (i.e., daddy longlegs) are arachnids but not spiders. They are harmless, despite myths that they are highly venomous. However, they can sometimes cause disruption when encountered by fearful students or teachers.

Contact your State Department of Natural Resources (or equivalent) to get info on spiders in the state, such as this resources, Common Spiders of Ohio Field Guide, from the Ohio Department of Natural Resources.

Stinging Insects

Although the vast majority of bee and wasp species are harmless, various species may sting when threatened. Because some students may suffer severe allergic reactions to stings, care should be taken to avoid contact with stinging wasps and bees while also allowing them to serve the important ecological roles of pollination and biological pest control.

Stings often occur when nests are disturbed, so controlling nesting is an effective way to manage risk in an outdoor learning environment. Check for nests monthly during the active season of June through October. Bees and wasps nest under the eaves of buildings, in cracks and voids in fences or walls, in hollow trees, and even in the ground in the case of yellowjackets. Nests that are located where there is low chance of contact should be left alone. However, nests that are in highly trafficked areas should be treated and removed. Aerosolized spray pesticides are effective but should be applied by a trained, licensed, and insured professional when bees and wasps are inactive (i.e., night, early morning). Honeybee swarms sometimes occur on and around school campuses and can be removed safely by local beekeepers or county extension agents.

Maintaining proper sanitation can also minimize contact with stinging insects. Many wasps, including yellowjackets, forage in trash for food. Using lidded trash cans with sturdy trash bags and removing trash frequently will reduce foraging opportunities significantly.

Stinging Ants

In the United States, three species of ant sting: the invasive red imported fire ant (southeastern United States, southern California), black imported fire ant (northern Gulf states, southeastern coast), and the southern fire ant (southern states from California to Florida). Their range is expanding because of climate change, with the red imported fire ant being most abundant. Another ant of concern, velvet ants (a.k.a. “cow killers”), are solitary wingless wasps that possess a very painful sting. However, they are generally not aggressive and will not sting if left alone, and do not form large colonies. As such, the best response allow them to pass.

As with bees and wasps, these ants generally sting only when a nest is disturbed, but, unfortunately, nests can be very common and easy to disturb. Fire ant stings can elicit a systemic allergic reaction in some individuals, making control essential where they are found. These ants can be controlled by broadcast pesticide treatment applied by a licensed, insured, and trained pest management professional.

Ticks

Ticks can be a pest of concern because of their potential to spread diseases like Rocky Mountain spotted fever and Lyme disease. However, not all ticks carry disease, so their presence should not prevent students from learning outside.

Ticks are most prevalent in forests or in fields at the edge of forested areas. In a school setting, ticks can be found in playgrounds, nature trails, athletic fields, and school yards. To greatly reduce the impact of ticks in the outdoor classroom, avoid contact with vegetation (e.g., hike in the middle of trails, stay out of tall brush), wear long pants tucked into socks, and check for ticks frequently. When ticks are found, they should be promptly removed using appropriate techniques.

Habitat modification is also effective. To make outdoor classrooms less suitable for ticks, reduce humidity by raking leaf litter, removing tall brush, and reducing shade. Exclude potential hosts, primarily rodents and deer, by removing cover such as rock walls and wood piles for rodents and replacing deer-friendly landscaping plants with less palatable alternatives. In some locations, deer exclusion fencing may be necessary.

Venomous Snakes

The best method for managing venomous snakes and other non-insect pests is to eliminate potential habitat for the animals. For example, eliminate damp and dark cover to make the school campus less suitable for venomous snakes. Additionally, removing habitat for rodents and other potential prey can reduce the possibility of a snake encounter. If venomous snakes pose a significant risk for the school, drift fencing can be erected, which excludes rattlesnakes and other reptiles.

Education and Behavior Modification

Education and behavior modification can reduce the risk of exposure to pests, and can help keep students, teachers, and staff calm and safe when they do encounter animals.

Prepare students. To help students prepare for an outing, instruct them in advance about what to wear, what to bring (e.g., repellent, allergy medication), and what animals they may encounter. Remind students to avoid using scented personal care products, especially those with floral or woodsy scents, as these may attract insects.

Let students know that most bugs are not a threat. Remind students that, with the exception of mosquitoes and flies, most pests are unlikely to be a threat or a distraction unless they are disturbed. Let students know that it is important to avoid disturbing local wildlife. Plan for how to relocate a distracting pest (or temporarily relocate the class) and for how to refocus the class after the disturbance.

Teach students about wildlife. Educate students on how to lift natural objects safely, where they should not put their hands (e.g., reach into holes or under brush), and how to identify venomous versus nonvenomous snakes and spiders.

Don’t panic. A panic response is never effective for avoiding bites and stings. In addition to educating students to remain calm when they encounter pests, be sure to confirm with school nursing staff that students with known allergies have medication on hand in the event of a sting.

© COMMUNITY CONSOLIDATED SCHOOL DISTRICT 46

© Sharon Danks, Green Schoolyards america

Key Issues to Keep in Mind

Many staff and students exhibit fear of animals, regardless of whether they are pests or not. For advice on how to deal with fear of animals or the outdoors, please see our article on ensuring a positive outdoor experience for students.

Personal protective measures (e.g., full-coverage clothing, insect repellent) may be an area where equity is a concern. Consider keeping extra supplies on hand, such as spare long-sleeved shirts or pants, in the event that students are unable to provide their own.

One of the great benefits of having class outdoors is the exposure to nature. Animals are a fascinating and vital part of the ecosystem, and management decisions should be made to protect the ways in which animals benefit the environment.

Be sure to contact your local county extension agent and your district facilities management before taking any pest management actions. Check state pesticide application and applicator regulations, and be aware of regulations for parental notification of pesticide applications.

Resources

School Integrated Pest Management

— IPM Institute of North America (2018). What is Integrated pest management (IPM).

— Cooper, J. C. (2018, July 26). “Integrated pest management: The “pest” defense for healthy schools.” GreenNotes. Green Schools National Network.

— Green, T. A., & Gouge, D. H. (Eds.). (2015). School IPM 2020: A strategic plan for integrated pest management in schools in the United States (Version 3.0).

— Northeastern IPM Center & New York State Integrated Pest Management Program. (2020). School IPM best practices.

— United States Environmental Protection Agency. (2017, May). Pest control in the school environment: Implementing integrated pest management (IPM) (USDA Publication 735-F-17-004).

Species Specific

Asian tiger mosquitos:
— Rios, L., & Maruniak, J. E. (2011). Asian tiger mosquito. Featured creatures. University of Florida.

Black flies:
— Hill, C. A., Platt, J., & MacDonald, J. F. (2010). Black flies: Biology and public health risk (Purdue Extension Publication E-251-W). Purdue University, Public Health, Department of Entomology.

Eye gnats:
— Machtinger, E., & Kaufman, P. E. (2011). Eye gnats, grass flies, eye flies, frit flies. Featured creatures. University of Florida.

Fire ants:
— Drees, B. M., et. al. (2020). Managing imported fire ants in urban areas. Ant pests. Cooperative Extension, United States Department of Agriculture.

Invasive plant species (in Arkansas):
— City of Fayetteville, Arkansas. (n.d.). Invasive plant species in Fayetteville, Arkansas.

Midges (no-see-ums):
— Connelly, C. R. (2013). Biting midges, no-see-ums. Featured creatures. University of Florida.

Snakes and rattlesnake bites:
— Cerato, M., & Andelt, W. F. (1998). Coping with snakes (Fact Sheet 6.501). (Revised by M. Reynolds). Colorado State University Extension.

Ticks:
— New York State Integrated Pest Management (n.d). How Do I Protect Myself From Ticks?

— New York State IMP Program. (2016). It’s tick season. Put away the matches.

Wasps, hornet, yellowjackets:
— Potter, M. F. (2018). Controlling wasps, hornets, and yellowjackets. University of Kentucky, College of Agriculture, Food and Environment.

Managing and Repelling Pests

Managing mosquitos and clothing:
— Whelan, C. (2020, August 24). Can mosquitoes bite through clothing? Healthline.

Reducing mosquitoes with fan wind:
— Hoffmann, E. J., & Miller, J. R. (2003). Reassessment of the role and utility of wind in suppression of mosquito (Diptera: Culicidae) host finding: Stimulus dilution supported over flight limitation. Journal of Medical Entomology, 40(5), 607–614.

Repellents:
— Lee, M. Y. (2018). Essential oils as repellents against arthropods. BioMed Research International, 2018, Article 6860271.

— Matsuda, B. M., Surgeoner, G. A., Heal, J. D., Tucker, A. O., & Maciarello, M. J. (1996). Essential oil analysis and field evaluation of the citrosa plant “Pelargonium Citrosum” as a repellent against populations of Aedes mosquitoes. Journal of the American Mosquito Control Association, 12(1), 69–74.

— Müller, G. C., Junnila, A., Butler, J., Kravchenko, V. D., Revay, E. E., Weiss, R. W., & Schlein, Y. (2009). Efficacy of the botanical repellents geraniol, linalool, and citronella against mosquitoes. Journal of Vector Ecology, 34(1), 2–8.

CREDITS

This article was written by Sim Barrow, environmental science coordinator, Fayetteville Public Schools, Arkansas; Michelle Niedermeier, school and community IPM program coordinator, PA IPM Program, Penn State University; Kathy Provenzano, Davis Elementary School, Austin Unified School District, Texas; and Ash Young, Vermont Wilderness School, Brattleboro, Vermont.

It was reviewed by Eric M. Cherry, MS, Principal Scientist, Hexagon Environmental, and Sarah Gill, MPP.

National COVID-19 Outdoor Learning Initiative

The National COVID-19 Outdoor Learning Initiative supports schools and districts around the country in their efforts to reopen safely and equitably using outdoor spaces as strategic, cost-effective solutions to increase physical distancing capacity onsite and provide access to abundant fresh air. The Initiative seeks to equitably improve learning, mental and physical health, and happiness for children and adults using an affordable, time-tested outdoor approach to keeping schools open during a pandemic.