Tiny Bugs on Deck & Wood: Harmless Barklice

New Hampshire homeowner finds microscopic, fast-moving brown bugs on deck, woodpiles, and family members. Birds' nest under deck has them too. Wife and kids feel "bitten," but homeowner feels nothing.

Identification: Barklice (Psocids)

Not true lice. Tiny (1-2 mm), soft-bodied, often with wings held roof-like. Feed on mold, fungi, algae, lichen on damp wood.

Why They're There

Deck wood has surface mold/fungi—perfect barklice food. They don't bite humans or pets. The "bites" are likely irritation from crawling sensation or other causes.

Solution

• Power-wash or scrub deck with deck cleaner to remove mold/fungi.
• Improve drainage/airflow to keep wood drier.
• Barklice will leave when food source is gone.

No insecticide needed. They're beneficial decomposers.