inquiline

1. (biology) An animal that lives commensally in the nest, burrow, gall, or dwelling place of an animal of another species.Examples: "The other study[…]involved the larvae of the caterpillar Maculinea rebeli, an inquiline of Myrmica schenki."; "Queens of socially parasitic inquiline ants reproduce by laying eggs in the colonies of other species."; "A reproductive female inquiline gains access to a host nest and usually kills the resident queen."

2. (biology) An organism that lives within a reservoir of water collected in the hollow of a plant stem or leaf.Examples: "Captured prey also constitute the resource base for a community of inquiline bacteria, protozoa, and invertebrates that inhabit the water-filled pitchers. For at least two of these inquilines (the pitcher-plant mosquito Wyeomyia smithii Coquillet and the pitcher-plant midge Metriocnemus knabi Coquillet) the availability of captured prey limits individual growth, and ultimately population growth[…]"; "The insect and other animal inhabitants of the pitchers, known collectively as the inquilines, may benefit the plants by breaking down prey and making nutrients available for plant absorption."