How to Keep Filthy Flies and Cockroaches Out of Your Facility

While it is true that every creature on Earth serves a distinct ecological function, there is one ecosystem where flies and cockroaches are not welcome: your food processing facility.

While it is true that every creature on Earth serves a distinct ecological function, there is one ecosystem where flies and cockroaches are not welcome: your food processing facility. Unfortunately, food processing facilites provide everything that these two pests are searching for β€” food, water, shelter and a warm environment.

How can you win the battle to keep your facility free of these pests and the contaminants and pathogens they carry? Integrated Pest Management (IPM) is the answer.

But first, there are a few things you need to know about flies and cockroaches.

Flies and cockroaches are considered two of the filthiest pests out there because both carry pathogens that can induce illness and, in the most severe cases, death. Flies are associated with more than 100 pathogens, including salmonella, staphylococcus, E. coli and shigella, while cockroaches are known to spread typhoid fever, cholera, gastroenteritis, listeriosis and giardia. Any association between your facility and these pests could be devastating to your business.

In addition, flies and cockroaches can reproduce quickly. The American cockroach can produce up to 90 egg cases (called oothecae) in her lifetime. Each of these egg cases contain around 15 embryos that will hatch in about a month. Flies are similarly prolific at reproducing; a single pair of houseflies can start a reproductive avalanche producing 1 million offspring in just a few weeks. Under ideal conditions a house fly can complete the lifecycle in just seven to 10 days.

Seeing a fly or cockroach usually means there are more present. The one or two you see could be representative of dozens, if not hundreds, more that could be hiding in your facility’s walls and crawlspaces. A pest sighting is a warning to take action immediately.

So what should you do? Implement an IPM program to assess the risk areas in your facility and establish tactics to prevent and keep pests out. IPM relies on chemical treatments only as a last resort, focusing instead on proactive preventing strategies like exclusion, facility maintenance, stringent sanitation practices and ongoing inspections to keep pests away.

In terms of preventing flies and cockroaches from entering your facility, there are some IPM tips that you can start using today.


Open doors and windows can serve as a welcome invitation into your facility for flies. The best way to avoid drawing them in is to eliminate attractants and block pests from entering as much as possible.

  • Clean up β€” Sanitation is an important way to help eliminate pests. Flies are attracted to food and sugary substances, so clean up messes as soon as possible after they occur. In addition, don’t forget to take out the trash on a regular basis.
  • Adjust outdoor lighting β€” Swap out mercury vapor lamps, which attract pests, with outdoor sodium-vapor lights, especially near entrances to your facility. There are also fly lights that can be placed away from a building to draw flies away and reduce their populations at the same time.
  • Use automatic doors β€” Automatic doors give flying pests less of an opportunity to get inside by reducing the amount of time that doors remain open. Installing two sets that only open once the other is closed to create a vestibule is an even better solution.
  • Inspect loading docks β€” Make sure that all doors form a tight seal when closed and are not left open for extended periods of time.
  • Seal any cracks β€” Even the smallest gaps can be big enough for flies to enter. Add door sweeps and weather stripping to minimize these. Use weather-resistant caulk to seal gaps on the exterior of your building.
  • Install an air curtain β€” Create an air β€œwall” flies can’t penetrate. You can do so by installing appropriately sized air curtain units β€” or fans β€” above exterior doors. Ensure these are maintained for proper air velocity and direction.
  • Create positive airflow β€” Positive air flow is when air is flowing out of your building instead of into it, which means that flies and other pests will be pushed out. Work with an HVAC professional to make sure you have positive airflow. To test for positive airflow yourself, hold a piece of tissue paper in a doorway and observe which way it blows.


Roaches are constantly scavenging, and food processing facilities are full of food sources for them. While exclusion practices like sealing openings and installing automatic doors can help with cockroaches as well, there are several other things to consider.

  • Store food securely β€” Make sure products are stored off of the floor and are sealed. In kitchens and other areas where employees store food, use airtight containers and empty trash bins at least daily to avoid food waste becoming a target.
  • Wipe down surfaces β€” The smallest crumb can be a meal for a cockroach. Make sure that employee break rooms are free of crumbs and food sitting out in the open, and clean up spills immediately. Sweep, vacuum and mop on a weekly β€” if not daily β€” basis to make sure that these areas are as free of food particles as possible.
  • Inspect incoming shipments β€” Cockroaches are skilled hitchhikers, so make sure there are no unwanted passengers in any packages entering your facility.
  • Remove clutter β€” Throw away clutter, especially unused cardboard boxes, to avoid giving roaches a place to hide out. Cockroaches can use cardboard for harborage and as a food source.

With both of these pests, it’s crucial to develop a pest sighting protocol. Everyone on your teams needs to know the signs of a fly or cockroach infestation and how to report any issues. Create and implement a written sanitation program and educate your staff on the critical role they play in preventing conditions that favor these pests.

Talk with a pest management professional about these and other IPM practices you can use at your facility to help prevent flies and cockroaches from getting inside and potentially ruining food products. Many pest management professional can also provide training and educational materials to help keep your staff up to date with the latest tactics for keeping pests away.

Using these techniques will help ensure that flies and cockroaches stay in their natural environment and out of yours.

About the author

Dr. Zia Siddiqi is Director of Quality Systems for Orkin.  A board certified entomologist with more than 35 years in the industry, Dr. Siddiqi is an acknowledged leader in the field of pest management.  For more information, e-mail [email protected] or visit