The Bulldog Rat was a species of rat endemic to the Christmas Island

Christmas Island

The Territory of Christmas Island is a territory of Australia in the Indian Ocean. It is located northwest of the Western Australian city of Perth, south of the Indonesian capital, Jakarta, and ENE of the Cocos Islands....

 in the Indian Ocean

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

. The rats lived on the higher hills and denser forests of the island. They had short tails and their backs were covered in a two centimetre thick layer of fat. They lived in small colonies, in burrows among the roots of trees or under hollow logs in primary forest. They were sluggish and never climbed and may have seemed half-dazed in daylight.