Earthworm
(Lumbricus terrestris)
The Common earthworm is not a glamorous creature, but its sterling work improving the soil it calls home makes it a true friend to other animals, including us.
There are 25 native species of earthworms in the UK but Lumbricus terrestris is the most familiar. It is large and reddish, usually 10-20cm long, with a soft, boneless body.
The body of the earthworm has lots of distinct segments (more than 100 in a large specimen). This is characteristic of the Annelids, the animal group to which it belongs. It has a small brain at the blunt “head” end.
Fascinating fact:
Each worm segment contains almost all the organs the animal needs to function. This is why, if a digging gardener accidentally cuts an earthworm in two, the front end will usually survive.
Common earthworms dig vertical burrows, heading deeper if it is very dry or cold.
They eat largely dead plant material and are essential for soil health, effectively both ploughing and fertilising by pulling rotting vegetation down into the earth. They are also an important food for many small birds and mammals.
Earthworms are very common and tend to be a bit more active at night. They only come up to the surface to feed.
They have both male and female organs and pairs can come together to mate, exchanging sperm. Fertilised eggs remain in a cocoon until they hatch then take about a year to grow into adults. Individual adults can live several years.
Earthworms are threatened in many places including Killearn by the introduced New Zealand flatworm, which came to Scotland in imported potted plants and soil. It eats the native worms and can drastically reduce their numbers, so check carefully for intruders when you bring new plants into your garden.
The common earthworm is widely used in powdered form in Chinese medicine and was considered by our ancestors to be something of a cure-all. It is closely related to the leech.
Did you know
When people saw dead earthworms on the ground after heavy rain they used to think they had fallen from the sky. In fact, rain can wash the worms out of their burrows, and since they breathe through their skin they can drown if they find themselves in water for a long time.