Throughout the "war to end all wars," cats were a common sight in the trenches and aboard ships, where they hunted mice and rats. Beyond their "official" duties, they were also embraced as mascots and pets by the soldiers and sailors with whom they served.

An estimated 500,000 cats were dispatched to the trenches, where they killed rats and mice; some were also used as gas detectors. At sea, cats had the run of the ship — a tradition dating back thousands of years. As the U.S. Naval Institute explains:

It is likely that the ancient Egyptians were the first seafarers to realize the true value of having cats as shipmates. In addition to offering sailors much needed companionship on long voyages, cats provided protection by ridding ships of vermin. Without the presence of cats, a crew might find their ship overrun with rats and mice that would eat into the provisions, chew through ropes and spread disease. The more superstitious sailors believed that cats protected them by bringing good luck. It was also common for crews to adopt cats from the foreign lands they visited to serve as souvenirs as well as reminders of their pets at home.

Ship's cat aboard the HMAS Encounter. [Wikipedia]

A gunner with the regimental cat in a trench. Cambrin, France, February 6th, 1918. [IWM]

"Togo", the cat mascot of the battleship HMS Dreadnought. [IWM]

Feline mascot named "Spark Plug." [Library of Congress]

"Pincher," the mascot of the HMS Vindex, sitting on the propeller of one of the sea planes carried by the ship. [Wikipedia]

Ship's cat strutting along the barrel of a 15-inch gun on the deck of the HMS Queen Elizabeth. Gallipoli Peninsula, 1915. [Bibliotheque nationale de France]

A Canadian soldier with "Tabby," his unit's mascot, on Salisbury Plain. September 27th, 1914. [IWM]

Two men of the 9th Battalion, Gordon Highlanders (15th Division) with their pet cat. "Martinpuich," August 25th, 1916. [IWM]

Two cats pose in the breech of a 4-inch caliber gun aboard an unidentified U.S. ship. [U.S. Naval Institute]

Studio portrait of a soldier holding a kitten. Melbourne, 1915. [Australian War Memorial]

Officers of the U.S. 2nd Army Corps with a cat they discovered in the ruins of Le Cateau-Cambrésis. [Pictorial Record of the 27th Division]

A sailor on board the Royal Australian Navy Destroyer HMAS Swan shaking the paw of "Ching," the ship's mascot. [Australian War Memorial]

Sailor on board the HMAS Melbourne holding two ship's cats. 1917. [Australian War Memorial]

Ensconced in an opening in a sandbagged dugout, a cat, probably a mascot, looks up expectantly at the approach of an unidentified soldier. Gallipoli Peninsula, 1915. [Australian War Memorial]

British soldier playing with mascot. [Illustrated War News, Vol. 7, London, 1918]

Portrait of Company O'Connor Men and cat. August 12th, 1915. [Australian War Memorial]

And, lastly, "Pitouchi" (photo below) was born in the trenches. His mother was killed when he was a kitten, and he was adopted and nursed to health by Lt. Lekeux of the Belgian army. According to the book, Soldiers in Fur and Feathers, by Susan Bulanda, the cat followed the officer wherever he went, and one day saved his life:

As Lekeux reached a spot near the German lines, he saw that they were digging a new trench. He hid himself in a shell hole nearby to make a sketch of the German works. He was so absorbed in his sketch that he did not notice approaching German soldiers on patrol. When he finally realized his situation, it was too late to run.

He decided to lie very still, hoping that the Germans would not see him, but unfortunately he heard one soldier say, "He's in the hole," so he knew he had been seen.

When Pitouchi heard the German say that, he jumped out of the hole onto a piece of timber. The Germans were startled and fired two shots at Pitouchi. However, as frightened as he was, Pitouchi was not hit, and he jumped back into the hole with his beloved Lekeux.

The Germans laughed and joked that they had mistaken a cat for a man and left. Lekeux finished his drawings and returned to the Belgian lines with Pitouchi on his shoulders.