Habits: The earthworm lives mostly underground, plowing through soil and creating complex burrow networks six feet or more. The earthworm’s body is a tube of muscle arranged in two layers. One set of fibers moves lengthwise like a girdle around its body. Tightening the girdle” forces the worm’s head forward like toothpaste squeezed out of a tube. A muscle contraction passes through the body, squeezing more of the worm up the tunnel until the long muscles can drag the tail forward and the contraction process starts again. Well lubricated with mucus, the worm can move through the hardest earth. The thin skinned earthworm has no resistance to the sun’s ultraviolet radiation so it only comes to the surface in wet weather. On rainy, wet nights it emerges to probe grasses and dead leaves for food or to mate.

Breeding: The earthworm has both male and female sex organs, but it cannot fertilize itself. It mates to exchange genetic material, similar to the way flowers cross pollinate each other. The earthworm mates on the surface at night. Drawn together by scent, the worms lie head to tail, enveloped in mucus. For an hour or more they exchange sperm and store it in a special pouch.
After separating, the worm secretes slime from its clitellum (the pale, swollen section toward the rear of its body). The slime dries into a tube that slips down the worm’s body, collecting eggs and sperm. The tube slips off and the ends seal to form a pea sized cocoon holding up to 20 earthworm eggs. The cocoon can survive drought and frost while adult earthworms cannot. Usually only one earthworm emerges from the cocoon.

Predators: The thrush, blackbird, and starling cock their heads and listen for worms moving underground. With a quick stab of the bill they catch the earthworm, but it uses tiny bristles on its body to anchor itself in the hole. A strong earthworm can break free, but sometimes part of it snaps off. If the break is near the end of the body, the earthworm can regenerate the missing part. Small animals like shrews, hedgehogs, badgers, foxes, and wolves all eat earthworms, and the mole eats about 50 earthworms a day – more in winter.

Food and Feeding: The earthworm eats the soil by crunching it in its muscular stomach, digesting organic material mixed in with the mineral fragments, and ejecting the rest. Some earthworm species dump waste on the surface, leaving coiled deposits called wormcasts, but others void waste below the ground. In old grassland soils, a cubic yard can hold to 500 worms. The soil becomes fertile as the worms leave a well drained, well aired, crumbly loam (soil with sand, clay, silt, and organic matter). The soil is very fertile because of a continuous turnover of nutrients from the lower levels to the surface. Acid moorlands contain few worms, causing the soil to be poorly drained, airless, compacted, and infertile. The earthworm also eats dead leaves after dragging them to its burrow.

Key Facts:
Sizes: 
Length: Usually up to 1 ft., but longer specimens are recorded

Breeding:
Sexual maturity: 6-18 months
Mating: On warm, wet summer nights
No. of eggs: Up to 20 per cocoon
Hatching time: 1-5 months

Lifestyle:
Habit: Solitary burrower, occasionally lies dormant in a burrow in very cold or dry weather
Diet: Soil containing organic matter, dead vegetation, sometimes small dead animals
Lifespan: Up to 6 years in captivity

Related Species: The 1,800 or so species of earthworms are relatives of the leech, marine ragworm, and lugworm.
Distribution: The earthworm is found worldwide. The common earthworm is found throughout Europe and Asia in suitable climates and soil.
Conservation: Some gardeners poison earthworms to eliminate wormcasts (waste deposits). Poisoning causes more damage to lawns, predatory birds, and other animals than to earthworms.

How the Earthworm Reproduces:
Mating: Attracted by scent, two earthworms exchange sperm on the soil’s surface, bound together by a mucus covering.
Preparation: The worm secretes mucus from its clitellum (the pale, swollen section of its body), forming a sheath.
Fertilization: The sheath slips down the body, collecting eggs and sperm.
Sheath: The earthworm slides out of the mucus sheath, slipping it over its head.
Cocoon: The sheath, containing up to 20 eggs, seals up to form a cocoon. It can survive extreme weather conditions, but usually only a single young earthworm emerges.

Did You Know: 
If an earthworm loses one end of its body it grows a replacement, but if it is cut in half it dies. It never becomes two new earthworms.
In 1982 an earthworm more than five feet long was found in Britain – a midget compared to the 10 foot earthworms found in southern Africa and Australia.
Earthworms slowly bring soil to the surface and cover objects on the ground. This is one reason why archaeologists have to dig down underneath the ground to find fossils

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