Three Cheers for Earthworms!
There are 29 different species of earthworms in the UK. Of these, 16 can be found in British gardens, varying greatly in size and colour. Charles Darwin was keen on worms, and thought few other animals played so important a part in the history of the world, which is quite a claim. He studied them for over 40 years at Down House which was then in Kent, now in the London borough of Bromley. One of his lesser known books is The Formation of Vegetable Mould Through the Action of Worms.
Earthworms break down plant matter, releasing nutrients to increase soil fertility. They do this by eating the organic matter in the soil, making it into smaller pieces, which they then pass out as casts.
A worm eats its own weight in organic matter and soil in a day, excreting much of this in casts. Their movement through the soil creates a networks of burrows and mixes the soil. These spaces bring oxygen into the soil, which is needed to break down organic matter, and is important for soil drainage.
The various of species of earthworms perform different roles in the soil, and can be divided into four main types.
Composter worms are found in garden compost and in rotting vegetation. They are excellent recyclers of green waste. They are generally bright red and stripy.
Epigeic worms live at the soil surface and help to break down leaf litter. They tend not to make burrows and are often bright red or reddy-brown but not stripy.
Anecic worms are deep burrowing worms who create vertical burrows, pulling down leaves from the surface. They usually have red or black heads and a paler tail.
Endogeic worms live in soil, eating and aerating the earth by making horizontal burrows. They are grey, pink, green or blue.
Earthworms are an important food source for many animals including robins, blackbirds, frogs, foxes and hedgehogs. Artificial grass is bad for them, blocking off oxygen, rain and having nil growth, becoming dead areas. Its the same for concrete paths. Separate slabs are much better.