Earthworms

Earthworms are incessant burrowers, moving through the soil to find food. A soil can support a large number of earthworms (up to 1600 in a square metre!). Their ability to tunnel through the soil makes highways for the movement of water, air and other animals to move around the soil quickly with no hindrance. Their ability to cast upon the surface loosens the soil up, and over many hundereds of years, has resulted in the burial of rocks and rubbish and over thousands of years, has hidden all evidence of ancient cities.

All gardeners are happy when they find earthworms in their gardens, because worms loosen the soil by burrowing and help speed up the process of decomposition, where compost is turned into nutrients for plants. Of course others are happy, because it is free bait so they can go fishing! 

Dung beetles
A pair of dung beetles burying a ball of dung

Dung beetles like their dung. They'll fly miles for it, and competition over a dung patch can sometimes be quite fierce. Dung bettles like dung because it is a great place to lay their eggs. It's warm and cosy, and when their young hatch, there is a whole cupboard of food just waiting to be eaten.

Dung beetle egg inside a ball of dung
When dung beetles find a dung patch, they collect some of the dung, roll it into a ball and then bury it in the soil. This can take a couple of hours. When the larvae hatch, and have finished the dung, they burrow through the soil. 


Larvae
The larvae of beetles and flies are often found in soil. Soil makes a great habitat to lay your eggs, because when the eggs hatch, they are not exposed to extremes of temperature, or quickly found by predators. There is also a smorgasboard of food in the soil...if you like that sort of thing of course. 

Ants
No one ever thinks of ants as lazy. Thats because they are always busy, tunnelling and collecting food. In some soils, ants are vitally important in recycling nutrients, increasing water infiltration and burying seeds. Ants are very prominant in Australia, and we have more species than any other country in the world. 

Termites
In many areas of Australia, termites have a big effect on the landscape. Their nests can be giant, multistoried towers of soil and organic matter, or they can live in a small nest inside a log. They play an important role in breaking up dead organic material, especially in tropical areas.

In urban areas, termites are a pest, because they tunnel through wood and threaten the structure of buildings.

Photographs on this page courtesy of
Dr. Clive Kirkby, Dr. Bernard Doube and John Buckerfield,
CSIRO Division of Soils
Dr. Geoff Baker,
CSIRO Division of Entomology