German soldiers posing in front of a dugout with rats they caught in their trench and with captured

German soldiers posing in front of a dugout with rats they caught in their trench and with captured French business signs. “Assurance against Thirst”. 
Although shooting at rats was strictly prohibited – being regarded as a pointless waste of ammunition – many soldiers nevertheless took pot shots at nearby rats in this manner. Attacking rats with bayonets was also common.