Good fly control is not one spray or one trap. It is an integrated routine that makes the farm less useful to flies as a place to breed, feed, and rest. Penn State's swine fly-control guidance specifically recommends an integrated pest-management approach built around identification, life cycle, monitoring, thresholds, and multiple control methods. [1]

Start Where Flies Reproduce

Wet organic material in a Kunekune pen showing where flies reproduce
Wet organic material, not just visible adult flies, is the source to find first.
Wet organic material in a Kunekune pen showing where flies reproduce
Wet organic material, not just visible adult flies, is the source to find first.

Walk the pig area looking for wet organic material: manure, soaked bedding, spilled feed, damp hay, leaking waterers, muddy feeding areas, and old material packed into corners. Adult flies are what you notice, but breeding sites are what keep the population coming back.

Manure and Bedding Management Come First

Illustrated comparison of muddy manure buildup beneath grazing pigs and a drier resting space, emphasizing removal of wet bedding.
Dry bedding and prompt manure removal make the pig area less useful to flies.
Split farm photograph contrasting a person removing wet manure from a muddy pig pen with pigs resting on clean, dry straw bedding.
Dry bedding and prompt manure removal make the pig area less useful to flies.
  • Remove concentrated manure and wet bedding before it accumulates.
  • Keep resting areas as dry as practical.
  • Clean feed spills rather than letting them ferment in damp bedding.
  • Keep manure or compost storage far enough from pig housing that it is not functioning as the barn's fly nursery.

Sanitation is not glamorous, but it is the part of fly control that makes every other method work better. [1]

Fix Water Leaks

Infographic showing a leaking water fitting dripping onto bedding beside a checklist of troughs, valves, hoses and drain areas to inspect.
Check the whole water path for leaks that keep bedding and manure damp.
A farm worker tightens a leaking connection beside a livestock water bowl in a muddy pen while a ginger Kunekune stands nearby.
Check the whole water path for leaks that keep bedding and manure damp.

A small leak can keep bedding and manure continuously damp. Check cups, nipples, hoses, valves, troughs, and drain areas. Repairing one persistent wet spot can matter more than adding another trap.

Use Traps Where They Make Sense

Farm layout showing attractant fly traps away from pig rest, feed, and door areas
Trap placement should intercept flies without drawing them into the main working area.
Farm layout showing attractant fly traps away from pig rest, feed, and door areas
Trap placement should intercept flies without drawing them into the main working area.

Traps can help monitor and reduce adult flies, but placement matters. Do not put strong attractant traps right beside doors, feed areas, or places where people and pigs spend time if that placement draws more flies into the working area.

Sprays Are a Tool, Not the Whole Program

Fly-control wheel placing manure sanitation in the center, with exclusion, traps, labeled chemicals and biological controls around it.
Sanitation, exclusion, traps, biological controls, and properly labeled chemical tools work together.
Farm fly-control scene labeling manure removal, dry bedding, water sanitation, traps and targeted spray around pigs and a barn.
Sanitation, exclusion, traps, biological controls, and properly labeled chemical tools work together.

If an insecticide is needed, use a product legally labeled for the site and intended use, follow the label exactly, and protect feed, water, people, and animals from inappropriate exposure. Rotating between sanitation, exclusion, traps, biological controls, and properly selected chemical tools is more consistent with IPM than repeatedly spraying without addressing breeding material. [1]

Fans and Air Movement

Blue arrows show a barn fan moving air across the pig resting area, with a note that ventilation complements rather than replaces cleaning.
Moving air can make enclosed resting areas less attractive to flies while improving summer comfort.
A worker adjusts a wall-mounted barn fan above spotted and ginger Kunekunes resting on straw, with airflow shown across the pen.
Moving air can make enclosed resting areas less attractive to flies while improving summer comfort.

Where electricity and barn design allow it, moving air can make enclosed resting areas less attractive to flies and can improve summer comfort. Fans do not replace manure or moisture control.

Watch the Pigs

Kunekune pig inspection points for eyes, ears, skin, and sore areas during fly season
Watch eyes, ears, skin, wounds, piglets, and nursing sows closely when fly pressure rises.
Kunekune pig inspection points for eyes, ears, skin, and sore areas during fly season
Watch eyes, ears, skin, wounds, piglets, and nursing sows closely when fly pressure rises.

Heavy fly pressure can make pigs restless and can aggravate wounds or sensitive areas. Check eyes, ears, skin, wounds, nursing sows, and young piglets closely when fly numbers rise.

BF Farm's Weekly Fly Routine

BF Farm daily, every-few-days, and weekly fly-control inspection routine
A repeated fly-control routine catches water leaks, wet feed, bedding problems, and overlooked breeding material.
BF Farm daily, every-few-days, and weekly fly-control inspection routine
A repeated fly-control routine catches water leaks, wet feed, bedding problems, and overlooked breeding material.
  • Daily: check water leaks, wet feed, obvious manure buildup, and animal irritation.
  • Every few days: refresh problem bedding and inspect trap performance.
  • Weekly: walk the full barn and fence-line area looking for overlooked breeding material.

The Bottom Line

If the farm stays wet and dirty, fly control will always feel like a losing battle. Drying and sanitation come first; traps and labeled control products come after.

Sources & References

  1. Penn State Extension: Fly Control on Swine Farms