Inquilines

Inquilines are organisms that reside in the dwelling of another species, the host, from which they derive resources such as food, shelter, or parental care, often without providing any reciprocal benefit. The term, derived from Latin inquilinus meaning tenant, is used in biology to describe tenants within another organism’s space, sometimes to the detriment of the host.

They occur across taxa, including birds and social insects. In birds, nest parasites such as cowbirds and cuckoos lay eggs in the nests of other species; the host incubates and raises the parasite’s offspring at the expense of its own. In social insects, inquilines inhabit the nests of ants, bees, or termites and may rely on host workers for food and brood care.

Some inquilines are obligate parasites that never establish a colony of their own; others are facultative, exploiting hosts opportunistically. They often manipulate host behavior or odors to avoid detection, suppress host reproduction, or reduce competition for resources. Termite and ant inquilines may remain in host nests permanently, whereas avian brood parasites facilitate their own reproduction by exploiting host parental care.

Ecological and evolutionary implications include effects on host fitness, colony dynamics, and the evolution of host defenses. The study of inquilines contributes to understanding parasitism, coevolution, and social organization in animals.