An ecosystem is a community of plants and animals and its environment.

Herbivores are animals that eat only plants.

Carnivores are animals that eat only meat.

Omnivores eat meat and plants.

Detritivores eat only dead, decomposing plant or animal matter, or droppings.

A Food chain is the transfer of energy from organism to organism.
They usually start with a green plant that gets its energy from the sun. Here is an example:

Grass - rabbit - fox.

The grass is a food producer because it produces food for animals.

The rabbit is a consumer because it consumes (eats) grass, it is also prey because it is eaten by the fox. Animals that are eaten by other animals are prey. Grass is not prey because it is not an animal.

The fox is a consumer because it eats the rabbit and a predator because it eats animals. Predators are animals that kill and eat other animals.

Here are some more food chains:

Leaf - caterpillar - bluetit - sparrowhawk.
Corn - mouse - owl.
Leaf - snail - song thrush.
Acorn - squirrel - fox.
Leaf - caterpillar - beetle - hedgehog - fox.
Blackberry - mouse - badger
Plankton - mussel - starfish - crab - otter
Grass - grasshopper - frog - heron

Food chains can become connected to form food webs. For example;
The fox could eat the hedgehog, the squirrel, the mouse, the song thrush, the snail and the beetle.
The song thrush could eat the caterpillar and the snail.
The mouse could eat the corn, the acorn, the snail, the beetle and the caterpillar.
The squirrel could eat the acorn, the corn, the caterpillar and the beetle.

Draw a picture to include all of the above animals and then draw lines between each animal and its food. You will then have a food web.

Life cycles:
Egg - larva - pupa - ladybird
Egg - larva - pupa - butterfly
Egg - larva - pupa - house fly
Egg - nymph - dragonfly
Egg - nymph - damselfly
Egg - nymph - mayfly
Frogspawn - tadpole - froglet - frog
Egg - young snail - adult snail