Don’t Fall Asleep on Flies this Winter

Flies are a pest commonly associated with summer but commercial facilities should not let their guard down this winter.
“Seeing flies inside an account during the winter months is not uncommon, especially with cluster flies,” says Ashley Roden, technical specialist for Sprague Pest Solutions. “They do not simply die off because its cold outside.”
Flies will enter the facility structures in the fall season through small gaps on the exterior or missing vent screens in search of a place to overwinter. They will often end up in drop ceilings and wall voids, and remain fairly inactive unless they are disturbed.
Roden says office buildings and healthcare facilities are two facilities where drop ceilings and fly issues are common. 
“Cluster fly infestations usually become noticeable when facility maintenance personnel are performing cleaning or repair tasks,” says Roden. 
When a ceiling tile with an infestation is moved hundreds, even thousands, of cluster flies will emerge and gravitate to lights – an unsettling sight for both clients and auditors.
“Flies present a very serious threat to healthcare and food processing facilities no matter the time of year since they are capable of transferring harmful bacteria to processed and unprocessed food, raw materials, food preparation surfaces and sterile room settings,” adds Roden.
In restaurants fly issues can be a year around problem since the warm, humid and moisture-filled conditions in kitchen and dishwashing areas provide flies with ideal breeding and harborage areas.
“The conducive conditions in floor and sink drains, lines and drip trays in beverage dispensers, and cracks and crevices in commercial kitchens enable house, blow and fruit flies to establish a foothold,” says Roden. “It is important for facility managers and the pest management provider to establish and follow good sanitation protocols.”
What can clients do to prevent flies from becoming a problem in their facility during the winter months? Roden offers these tips:
  • Seal gaps and openings – If the weather permits do an inspection of the exterior of your building and seal gaps and openings, and repair screening to deny flies access.
  • Inspect drop ceilings regularly – Ideally it is best not to have drop ceilings but if that can’t be changed these areas need to be regularly inspected and cleaned of dead flies that can attract other pests including destructive stored product pests.
  • Lighting – If your facility has a recurring problem with flies in drop ceilings consider having your pest management provider install insect light traps. These traps will capture flies on sticky boards and keep the area pest-free.


Flies & Moths