February 1st, 2026
When the climate gets extreme, so do the pests: building resilience against flies and cockroaches
By Robert Jones, Arctech Innovation
Unlike many climate-sensitive health risks, flies and cockroaches respond quickly to improvements in environmental management, hygiene, and infrastructure. Building resilience against pest-driven disease requires integrating pest ecology into how we plan for future climate extremes.
Bringing pest ecology into climate resilience planning
Flies and cockroaches are predictable. Food, water and harbourage regulate their population size and density, and surges can follow events that increase exposure to waste, warmth and moisture.i,ii Recognising domestic pests as climate-sensitive health risks, adding pest exposure pathways to vulnerability assessments, and anticipating early post-disaster population expansions are ways of integrating pest ecology into resilience plans and shifting pests from a reactive control problem to a preventable exposure risk.
Strengthening WASH systems for post-disaster pest control
Water, sanitation, and hygiene systems are central to pest resilience. Climate-resilient WASH design can limit pest breeding even under extreme conditions, but need to consider how and where pest populations can bloom. Approaches to consider include the use of flood-resistant latrine designs and waste containment, rapid restoration of refuse collection after disasters, and drainage systems that prevent organic build-up. Safe food storage and preparation spaces also need to be made available in emergency settings. These approaches limit access to material used by pests for laying eggs and immature development, and allow WASH systems to act as pest control by design.
Climate-resilient waste management
Flies and cockroaches thrive on waste, yet waste management is often deprioritised during emergency response because of other priorities and limited resources. Resilient strategies should consider temporary waste containment solutions for flooded areas, contingency planning for disruptions to refuse collection, and clear responsibilities for waste management in humanitarian settings. These measures can reduce pest populations while improving living conditions.
Household and community hygiene interventions
The UNHCR recommends decentralised household level solid waste management solutions, as well as recycling and reuse, where possible, and encourages strong community engagement.iii At the household level, small interventions can have big effects. For example, covering food and garbage bins, safely disposing of organic waste, and sealing cracks and entry points can restrict access by domestic pests, and regular surface cleaning, can reduce the possibility of onward transmission of pathogens.iv,v Community-led hygiene initiatives can sustain these practices during prolonged recovery periods, especially where formal services lag.
Pest-linked early warning indicators
Because flies and cockroaches respond rapidly to environmental change, they can serve as early warning indicators of deteriorating sanitation and rising disease risk. Simple monitoring of sudden increases in indoor fly density or cockroach sightings can signal when interventions are needed before disease outbreaks occur. Integrating these indicators into climate-health surveillance could strengthen preparedness at low cost.
Emergency shelters and humanitarian settings
Emergency shelters are high-risk environments for pest-driven transmission. Designing pest resilience into shelters includes ensuring adequate spacing and ventilation, dedicated waste and food preparation areas, routine cleaning protocols, and rapid-response pest management that prioritises safety.vi,vii In these settings, pest control is a public health safeguard.
Closing thought
Climate change is already reshaping how diseases spread. But some of its most immediate health effects emerge not from exotic pathogens or distant vectors, but from familiar insects that live in our and around our homes. Building resilience against flies and cockroaches is not a distraction from climate adaptation, but one of its most practical and immediate wins – reducing disease risk through interventions we already know how to implement, even under extreme conditions.
Robert Jones has been supported by an unrestricted donation to LSHTM from Reckitt PLC for research on the intersection of hygiene and health.
References
[1] Owens, 1980. Some aspects of German cockroach population ecology in urban apartments. Thesis: Perdue University. Available from: https://docs.lib.purdue.edu/dissertations/AAI802
[ii] Hiscox et al. The impact of adverse weather events on cockroaches and flies, and the possible effects on disease. Med Vet Entomol. 2025 Sep;39(3):500-514. doi: 10.1111/mve.12797. Epub 2025 Mar 7
[iii] UNHCR, 2025. https://emergency.unhcr.org/emergency-assistance/water-sanitation-and-hygiene/wash-emergencies
[iv] British Pest Control Association, 2025. Pest advice for controlling cockroaches. https://bpca.org.uk/test-news/page-82/cockroach-control-how-to-get-rid-of-cockroaches-bpca-a-z-of-pests/189168
[v] Centers for Disease Control and Prevention, 2025. How and when to clean and disinfect your home. https://www.cdc.gov/hygiene/about/when-and-how-to-clean-and-disinfect-your-home.html
[vi] UNHCR, 2025. https://emergency.unhcr.org/emergency-assistance/shelter-camp-and-settlement/shelter-and-housing/emergency-shelter-solutions-and-standards
[vii] APIC Emergency Preparedness Committee, 2008. Infection Prevention and Control for Shelters During Disasters.