Cimex lectularius, commonly known as the common bed bug, is a small, wingless insect that feeds on the blood of humans and other warm-blooded hosts. It is reddish-brown, flat, and oval-shaped, making it adept at hiding in crevices. Bed bugs are primarily nocturnal and are known for their resilience and ability to reproduce quickly. They thrive in environments where humans or animals are present, often hiding in mattresses, bed frames, and furniture.

Cimex lectularius, commonly known as the common bed bug, is thought to have originated in the Middle East, specifically in regions with temperate climates. Historically, it has been associated with human habitats across Europe, Asia, and the northern parts of Africa.

Cimex lectularius thrives in temperate climates, typically in regions where human habitation occurs. The species is well-suited to environments where temperatures range from 16-30°C (60-86°F), making indoor human environments ideal due to their consistent temperatures and humidity levels.

The ecological niche of Cimex lectularius is closely associated with human environments. They inhabit areas near sleeping quarters, such as mattresses, bed frames, and furniture, where they have easy access to human hosts for feeding. Their adaptation to human dwellings allows them to exploit the consistent conditions provided by indoor environments, enabling their survival and proliferation.