Dung Fly Identification Guide
Learn to identify dung flies by their bristly bodies, often golden or gray coloring, and their near-constant presence around fresh animal droppings.
Read the full Dung Fly encyclopedia entry →
Key Visual Features
Dung flies (family Scathophagidae, with the well-known yellow dung fly among them) are bristly, robust flies commonly seen around livestock and pasture areas.
- Size: Roughly 6-11 mm depending on species and sex, medium-sized for a fly.
- Color: Varies by species — often gray, brown, or golden-yellow, sometimes with darker mottling on the wings or abdomen.
- Body shape: Sturdy and somewhat hairy, with a slightly humped thorax and a tapering abdomen.
- Wings: Clear to lightly tinted, held slightly spread or angled over the body at rest, often longer than the abdomen.
- Legs: Long, bristly, and well-developed, frequently used to grip prey or mates on the dung surface.
- Antennae: Short and stubby, typical of most true flies, with a small bristle (arista) extending from the last segment.
Where and When You'll See Them
As their name suggests, dung flies are almost always found on or near fresh animal droppings in pastures, farmland, and grassy fields, where females lay eggs and larvae develop. Adults are also active predators, perching on dung to ambush smaller insects that visit the same spot. They are most visible on sunny days in spring through fall, especially in cooler climates where certain species are more cold-tolerant than many other flies.
Similar-Looking Bugs
- House flies: Grayer and less hairy overall, and not as tightly associated with fresh dung as a hunting perch; dung flies are noticeably bristlier.
- Flesh flies: Larger and more heavily built with a checkered gray-and-black abdomen pattern, typically found on carrion rather than dung.
- Blow flies: Often metallic green or blue and much shinier, lacking the dull, bristly, golden-brown look common in many dung fly species.
Quick ID Checklist
- Bristly, robust body, often gray or golden-yellow
- Long legs used for gripping while perched on dung
- Found directly on or hovering around fresh animal droppings
- Slightly humped thorax with a tapering abdomen
- Active in sunny pasture or farmland settings, spring through fall
Frequently asked questions
How do I know if a fly on manure is a true dung fly?
Look for a bristly, robust body with long gripping legs and a color ranging from gray to golden-yellow; true dung flies are almost always found directly on or hovering close to fresh droppings, often perched and watchful rather than just passing by.
Are dung flies the same as house flies?
No, dung flies belong to a different family and are generally bristlier, more robust, and specifically tied to fresh dung habitats, whereas house flies are grayer, smoother-bodied, and found in a much wider range of settings.
Why are dung flies often seen sitting still on manure?
Beyond breeding there, adult dung flies are active predators that perch on the dung surface to ambush smaller flies and insects attracted to the same spot.
What color are most dung flies?
Coloring varies by species, ranging from dull gray or brown to a distinctive golden-yellow seen in some of the most commonly noticed species.