Earthworms (500g) 
Contemporary planetary issues: energy, soil
Cognitive objectives:
Understand the formation of an example of soil.
Concretely visualise the role of earthworms in soil formation, particularly in its aeration, which facilitates the development of plant roots. The activity of earthworms has an essential ecological role. They are involved in the recycling of organic matter and aeration and drainage of rainwater in soils. Earthworms are the first mass of terrestrial living organisms.

Characteristics of the model:
The model consists of a wooden frame with two grooves and four Sheets: two in transparent plexiglass and two opaque.
It's the equivalent of an aquarium but completely flat. The top is open.
Dimensions (W x H x D): 400 x 300 x 70mm
Proposed activity:
In our earthworm farm, there are layers of soil of different colours and litter (including leaves) on top.
Earthworms are inserted into this device and it is closed. The opaque Sheets make it possible to plunge the box into darkness and facilitate the observation of the earthworms when they are removed (because earthworms have a tendency to flee the light). We can thus see how earthworms participate in the mixing of the earth and the degradation of the leaves.
Note: Earthworms are quickly eliminated from pesticide-treated soil. The human influence on the biodiversity of plant fauna and the microfauna of a soil can be explained.