This bill, known as the "TRANS MICE Act," aims to prohibit the use of federal funds for specific types of animal research. It broadly bans federal funding for any research that seeks to alter the biological sex of certain non-human vertebrate animals. Specifically, the legislation defines "covered research" as studies involving drugs, hormones, surgery, or other interventions designed to change an animal's body to no longer correspond to its natural biological sex. This includes research that disrupts development, inhibits natural functions, or modifies the physical appearance of the animal. The prohibition applies to "qualified animals," which encompass most non-human vertebrate species such as mammals, birds, fish, reptiles, and amphibians. However, it explicitly excludes animals that naturally change sex during their lifetime or possess both male and female reproductive organs.