Likely booklouse (psocid)

Humid indoor spaces, especially cupboards, stored books, paper, and pantry goods.

Molds, fungi, algae, and microscopic debris; may also feed on starchy materials in stored goods.

Small, soft-bodied insects that hide in cracks and favor damp conditions. They reproduce readily indoors when humidity is high.

Harmless to people and pets; they do not bite. Large numbers can contaminate or damage stored foods, books, and paper.