Worms are not often at the forefront of our minds, but perhaps they should be. 

Now the soil isn’t bone dry thanks to the recent downpours, me and the rest of the ecology team at Hampshire & Isle of Wight Wildlife Trust have been out doing worm surveys on our nature reserves. These involve digging into the soil and seeing what we find beneath the surface. Any worms we find are divided into four main groups: endogeic, epigeic, anecic, and compost.  

Endogeic worms are the most common worms in arable fields, they live in and feed on the soil itself and so burrow horizontally through the soil. Epigeic worms live in the topsoil among the leaf litter. Whereas anecic worms – the biggest worms in the UK – are deep burrowing worms that feed on leaves which they drag deep down into their burrows. The final group of worms, composting worms, are most likely to be found in areas of rotting plants or food. 

But why do we spend hours counting worms in the mud? Well, worms are vital for several reasons. Firstly, each group of worms has an important role in the environment. Worms are often called ‘ecosystem engineers’. Their burrowing produces holes within soil that allow water and other elements, such as oxygen and carbon dioxide, to move between the air and the soil. This small act can help prevent disasters, such as flash flooding and erosion, and allows plants to access vital water sources during drought.  

Another huge benefit of worms is nutrient cycling and decomposition. Endogeic and epigeic worms break down waste material and turn it into easily accessible nutrients. The worms decompose dead plant and animal matter and drag it deep into the soil. As they burrow, the nutrients mix in the different soil layers and these can then be accessed by living plants. Nutritiously enriched soil is advantageous not only to plants but to home gardeners, allotment holders, and farmers as well. 

Worms can also act as indicator of toxicity and pollution in our soil, alerting us to any problems and cleaning contaminated land through ‘bioremediation’ – the process where living organisms convert toxic pollutants into non-toxic substances. Earthworms are also a vital food source for some of our favourite British species, from hedgehogs to robins to frogs. 

So, when you next see an earthworm, remember all the important work they do for us. Worms really are wonderful.