Deer fly identification (Chrysops spp.)


Insect identifier · Biting flies

How to identify a Deer fly

Chrysops spp.
· Also called deerfly, chrysops, yellow fly, deerfly bite, fly that bites your head

Deer fly identification photo

The fly that circles your hat and bites your scalp in woods is usually a deer fly (Chrysops), not a horse fly.

Circles the hat, bites the scalp, yellow-black, bright eyes, woods on a sunny day. That is Chrysops. Horse flies are the bigger silent ones on legs. Mosquitoes hum and probe. A drop of blood and a welt that itches for days is typical. Hats help more than people think.

What does a deer fly look like?

Bright yellow-black patterned flies, often iridescent eyes, about housefly-plus size. Smaller than horse flies.

Deer fly (Chrysops spp.) is About 6–10 mm. Colors people notice: yellow, black, gold. Field marks: Bright yellow-black patterned flies; Often iridescent eyes; Circle the head persistently; Bite on the scalp, neck, and shoulders. It is found outdoor. If those marks are missing, open Horse fly, Yellow fly, Eastern yellowjacket before you force this name. Search phrases that belong on this page include what a deer fly looks like and deer fly identification.

Identification marks

  • Bright yellow-black patterned flies
  • Often iridescent eyes
  • Circle the head persistently
  • Bite on the scalp, neck, and shoulders

Size: About 6–10 mm
Colors: yellow, black, gold
Where: outdoor

What a typical deer fly bite looks like

Typical deer fly bite or sting
A typical pattern. Reactions vary. This is a guide photo, not a diagnosis.

Immediate sharp pain, then a raised itchy welt that can leak a drop of blood. Welts may last days. Daytime, head/neck/shoulders.

People searching “deer fly bite identification” want the pattern, not a single anonymous bump. Immediate sharp pain, then a raised itchy welt that can leak a drop of blood. Welts may last days. Immediate steps on this page: Wash; pressure if it bleeds; Cool compress and itch balm; Watch for infection if you scratch open; Move out of sunlit trail edges if they swarm. This species does bite or sting people. Fever, spreading redness, trouble breathing, or a child with many stings is professional care.

If you were bitten

  1. Wash; pressure if it bleeds
  2. Cool compress and itch balm
  3. Watch for infection if you scratch open
  4. Move out of sunlit trail edges if they swarm

Deer fly vs Horse fly

Deer flies target the head and are yellow-black with bright eyes. Horse flies are larger, stouter, and hit legs and back. Mosquitoes are quieter and do not slash.

Range and season

Throughout North America near woods and water, late spring–summer.

Woods and wetlands continent-wide, bright days in late spring and summer.

Throughout North America near woods and water in warm months.

Late spring–summer, bright days

Common questions

Deer fly vs horse fly?

Deer flies are smaller, often yellow-black, and target the head. Horse flies are larger and stouter, often biting legs and back.

Do deer flies spread disease?

In North America they are mainly a painful nuisance; they can mechanically move some pathogens but that is uncommon.

Why do they chase my hat?

They are attracted to movement and dark silhouettes against the sky.

What fly bites your head and neck?

Deer flies. They circle persistently in woods and wetlands on bright days.

Related identification pages