Potty Gardening Club: Earthworms
One of the most important creatures in your garden is not always easily seen. It lives beneath the ground tunnelling by eating the soil, breaking it up and carrying compost down into the ground. Worms eat their own weight in organic waste, soil and minerals and pass out their own weight in casts (worm poo) each day. The casts help to enrich and fertilise the soil. A field size area full of earth worms can break up about 50 tonnes of soil. There are about 16 species of earthworm in the UK with more than one species living in your garden. Different species of worm vary in size and colour, but all are important in creating good fertile soil.
We all know what a worm looks like – they have a long segmented body with a head end and a tail end, but did you know they also have bristles on their bodies that help them move, both on the surface and for pulling them along beneath the soil? Take a look at the close up pictures I have taken. The white dots are the bristles and you can see them clearly on one picture. You may want to find a worm yourself and look at it through a magnifying glass to see them.
You can also make a worm jar to observe how they move through the soil and how they mix it up (instructions here). Worms breathe through their skin, which must remain moist to enable them to absorb oxygen from the air, so they like damp but not wet conditions. Worms do not have eyes but have light sensing cells on their body to help them escape the light and sunshine which will dry them out and kill them. Worms lay eggs that look like a small yellowish or brown pea. You may have seen one of these when you have been digging in your garden. They do not need another worm to reproduce. When it’s very hot in summer or cold in winter worms burrow very deep into the soil to survive. Worms are tough little beasties. It is estimated that if worms were our size they would be at least 600 to 1000 times stronger than a human, so it’s a good job they are small. Worms can live up to 10 years and they have existed for about 600 million years.
Worms sometimes come to the surface to escape moles which eat them or when we have a lot of rain. In parts of the UK, Worm Charming competitions take place to try to replicate this. The world record of June 29 2009 is held by a 10 year old girl of Willaston, England, who raised an incredible 567 worms during Britain’s World Worm Charmer competition. Have a go at the Potty Gardeners Club Worm Charmer Challenge: follow the instruction and rules of the game here. Let us know how you did.
Good luck worm hunters.
Written by Rob Gagliano, Casual Learning Development Leader and Natural Science Collections Volunteer