guinea pig

The phrase "guinea pig" can have two different meanings: 1. Domesticated rodent species: A guinea pig is a small, domesticated rodent belonging to the Cavia porcellus species. It is often kept as a pet and is known for its docile nature and sociability. 2. Experimental subject: "Guinea pig" can also refer to a person or animal used in scientific experiments or tests. In this context, a guinea pig is often used to test the safety, effectiveness, or side effects of a product or procedure before it is used on humans. The term originates from a historical practice of using guinea pigs in biomedical research due to their perceived similarity to humans.