House Mouse on the Farallon Islands NWR (IMAGE) Louisiana State University Caption House mice were unintentionally introduced to the Farallon Islands National Wildlife Refuge, home to the largest seabird breeding colony in the contiguous US, and the population has grown to about 50,000 house mice inhabiting the island roughly the size of two football fields. Credit Point Blue Conservation Science Usage Restrictions N/A License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.