Which arachnid is the most common house-dwelling species worldwide?

Several spider species thrive alongside humans, but house-dwelling spiders in the family Theridiidae are especially widespread. Species such as the common house spider have adapted well to indoor environments, where they catch flies and other small insects. Their success comes from flexibility, tolerance of human structures, and a steady food supply. While exact global abundance is hard to measure, these spiders are among the most familiar arachnids in homes.