Abstract: The focus of the study on the history of WWI has gradually changed in the 20th century. The neo-military historians and environmental Historians focus on their studies on the subjects inadequately investigated by the traditional historians. From a perspective of environmental history, the relationship between rats and troops well demonstrated the interaction between the environment and human beings. Trench Journals and Unit Magazines published at that time by both sides complained that the rat issue was a chronic problem with the trench troops during WWI, and the relationship between rats and humans kept changing as well. After their attempts to trap and kill out the rats failed, the trench troops had to coexist with the rats which became a cultural sign on the Western Front in WWI.

Key words: World War I, the Western Front, trench journal, unit magazine, rats