In a few hours of the cloths re-worn the body's heat caused the eggs to hatch.
Lice also caused a disease called the trench fever. ˜Trench fever is an infective disease described by sudden start of fever, headache, sore muscles, sore bones and joints or rashes of skin injuries on the chest and back' according to the editors of The Encyclopedia Britannica. To recover from this infectious disease, they had to go out of trenches. It took about six weeks to recover. It wasn't found out till 1918 that lice were responsible for trench fever. Frogs by were found in crust pits filled with water. They were also found in the base of trenches. Slugs and horned beetles packed the edges of the trench. Many of the soldiers shaved their heads to prevent nits.
Trench Foot.
Trench Foot was another dangerous disease. It was a fungal infection of the leg caused by cold, wet and unhygienic surroundings. It could turn decaying and result in amputation. Trench Foot was more of a problem at the beginning of trench warfare as conditions improved in 1915 it rapidly decreased, however a small amount of cases continued during the war.
The Trench Cycle.
Normally a battalion would be needed in the front line. Then some time is spent in support. A period of rest would continue (generally short in duration) before the whole trench cycle would start again. In reality the cycle was depend on the needs of the situations faced by the army. Even at rest, men would be given tasks with duties that assigned them in the line of fire. Others would spend a very long time in the front line than usual, generally in the more 'tiring' sectors. ˜The numbers varied widely - a man might expect in a year to spend some 70 days in the front line, with another 30 in nearby support trenches. A further 120 might be spent in reserve. Only 70 days might be spent at rest. The amount of leave varied, with perhaps two weeks being granted during the year.