- Bed bugs and dust mites primarily appear due to dirty, damp, and unsanitary living environments, or spread through personal items/old furniture from infested areas. They "hitch a ride" on clothing, luggage, mattress/wall crevices, seeking warmth and food sources (human/pet blood). Bed bugs and dust mites live and breed in crevices, mattresses, bedding, upholstered furniture, spreading through luggage when traveling, in hotels, or through walls, pipes, and old items, thriving in crowded and poorly sanitized places.