How to Get Rid of Flies Outside in Warm Winters

How to Get Rid of Flies Outside in Warm Winters

Warmer-than-normal Missouri winters can keep flies active longer than usual and even bring them out on sunny midwinter days. That means more buzzing around doors, patios, and livestock areas—and more reason to stay ahead of them with smart prevention and targeted pest control from Bug-A-Way.​

Why Warm Winters Mean More Flies

In a typical cold winter, many flies die off or go dormant, especially outdoor species like house flies and cluster flies. When temperatures stay milder, more flies survive, breed earlier, and become active on warm days, increasing nuisance activity around homes and businesses. Cluster flies, for example, overwinter in wall voids and attics, then emerge into living spaces when winter sun warms the structure.

For Missouri homeowners, that can look like:

  • Flies gathering on the sunny side of the house, especially south- and west-facing walls.
  • Slow, “sleepy” flies appearing in upper rooms or around windows on warm winter afternoons.

How Long Do Flies Live?

House flies, one of the most common pest flies around Missouri homes, have relatively short lifespans but reproduce quickly. Most adult house flies live about 15–30 days, depending on temperature and access to food. In warm conditions with plenty of organic material to feed and breed in, they can complete their life cycle in as little as a week or two, allowing many generations in a single season.

Milder winters mean:

  • More adults survive instead of being killed by hard freezes.
  • Breeding can resume earlier in spring, leading to larger populations by summer.

Missouri Flies You’re Likely to See

Around homes in Missouri, the main troublemakers include:

  • House flies: Gray flies that breed in garbage, manure, and decaying organic matter and frequently invade kitchens, patios, and barns.
  • Cluster flies: Slightly larger, often gathering in groups on siding and overwintering inside walls and attics.

Warm winters help both types stay active longer, especially near livestock, dumpsters, and poorly managed trash areas.

How to Get Rid of Flies Outside (Actionable Tips)

You can significantly reduce fly activity outside with a few focused steps:

  • Eliminate breeding sites:
    • Keep trash cans tightly closed and clean up spills promptly.
    • Remove pet waste and fallen leaves or rotting fruits that provide food and breeding sites.
  • Improve yard sanitation:
    • Clean grills, outdoor tables, and food prep areas after use.
    • Rinse recycling bins and keep compost covered to cut down on odors that attract flies.
  • Use physical and targeted controls:
    • In problem areas, professional-grade residual treatments on fly resting spots (eaves, porch ceilings, sunny exterior walls) can dramatically reduce populations—these are best applied by licensed pest professionals.

Warm winter days are a great time to do preventive clean-up and exclusion so you are not overwhelmed when spring fully arrives.

When to Call Bug-A-Way

If you’re seeing clusters of flies inside on mild winter days, heavy fly activity around doors or barns, or recurring problems despite good sanitation, it’s time to call Bug-A-Way. Our team can:

  • Identify which fly species are causing trouble around your Missouri home or business.
  • Target key resting and breeding areas with professional treatments not available over the counter.
  • Recommend practical, long-term sanitation and exclusion improvements tailored to your property.

Warm winters do not have to mean a season full of flies. Contact Bug-A-Way for an inspection and customized fly control plan that keeps your outdoor spaces—and indoor peace—protected all year long.