Hawadax Island is an island in the Rat Islands archipelago of the western Aleutian Islands in the U.S. state of Alaska. The island was formerly known as Rat Island until May 2012 when it was renamed Hawadax Island, which is an Aleut name meaning "entry" and "welcome". The island has a land area of 10.3126 sq mi (26.7095 km²) and no permanent population. It is within the Alaska Maritime National Wildlife Refuge. It is 9.3 miles (15 km) in length and 3.1 miles (5 km) in width.

The brown rat, also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat and Norwegian rat, is a widespread species of common rat. One of the largest muroids, it is a brown or grey rodent with a body length of up to 28 cm (11 in) long, and a tail slightly shorter than that. It weighs between 140 and 500 g. Thought to have originated in northern China and neighbouring areas, this rodent has now spread to all continents except Antarctica, and is the dominant rat in Europe and much of North America. With rare exceptions, the brown rat lives wherever humans live, particularly in urban areas.