Bird Mite
Scientific Name: Ornithonyssus sylviarum or Dermanyssus gallinae
Order & Family: Order Mesostigmata, Family Macronyssidae or Dermanyssidae
Size: Minute, approximately 0.5 to 1.0 mm (hardly visible to the naked eye, appearing as a tiny moving speck)
Natural Habitat
Commonly found in bird nests (especially pigeons, starlings, or sparrows) under eaves, in attics, or window ledges; they can enter homes when birds leave the nest.
Diet & Feeding
Blood of birds (preferred host), though they will bite humans and other mammals if their primary hosts are unavailable.
Behavior Patterns
They are semi-transparent when hungry and turn reddish-brown after a blood meal. They are highly active and can swarm indoors in large numbers after birds fledge or a nest is abandoned.
Risks & Benefits
They pose a risk of dermatitis and intense itching from bites in humans. While they cannot complete their life cycle on human blood, they cause significant irritation/stress. No known ecological benefits in household settings.
Identified on: 2/14/2026