The role of insects

What are insects?

All creepy crawlies are invertebrates, but they’re not all insects. Insects always have six legs. Spiders are arachnids (the same family as scorpions), slugs and snails are molluscs, and centipedes and millipedes are in their own group called myriapods. Woodlice are actually crustaceans, like shrimps!

Cardinal beetle

Why are they important?

The ‘B’ in RSPB might stand for birds, but we also love insects. Why? Well, apart from being super-interesting in their own right, they’re also a vital part of the ecosystem. Or, to put it another way, a lot of birds eat insects, so without insects, we wouldn’t have a lot of birds!

Another crucial role that insects play is in pollination, helping plants turn their flowers into fruits. (Who loves apples?) They also contribute to the breakdown of plants and animals after they die, helping to keep our environment clean.

Because they’re key to so much in nature, insects can also alert us to environmental issues that we might not otherwise notice so quickly.

Apple blossom

What eats insects?

If your garden is full of plump insects, it will probably be full of other wildlife as well.

Many of our birds eat insects, and some eat them all year round, even migrating long distances to make sure they always have an abundant supply. Others eat them in the summer months and switch to a more varied diet in winter, when there are fewer insects around. Lots of species also feed insects to their chicks.

Some of our garden birds that rely on insects include house sparrows, blackbirds, wrens, swallows, robins and many more. The quantity of insects they can eat is staggering. It’s estimated that blue tits feed their chicks up to 10,000 caterpillars every day!

But it’s not just birds that eat insects. They’re an important part of the diet of hedgehogs, spiders, bats, fish, frogs and toads. Even some insects eat other insects, including wasps, beetles like ladybirds, and ants.

Robin perched on post in garden with autumn cotoneaster foliage in foreground

What do insects eat?

Most insects feed on plants, eating things like pollen and nectar, leaves or wood, and moulds. A few species, like midges and mosquitos, eat blood, and some, like dor beetles, even eat poo!

If you’ve got a garden, you can help insects by providing plants for them to eat. Bees, butterflies, hoverflies, flies and some moths feed from flowers. They like simple flowers and are perfectly happy with what we might call ‘weeds’, plants like dandelions, daisies and thistles. If you want to grow flowers for them, good choices are things like sunflowers and borage, or you could plant spring bulbs such as crocuses, or a climbing plant like honeysuckle or ivy.

For insects that prefer the green parts of plants, it’s also good to grow a range of things, as some species are very picky. White plume moths, for example, like bindweed, while orange-tip butterflies prefer nettles.

Bee on flower

Other ways to help

There are loads of ways that you can help insects. You could put up nest and hibernation boxes or make a wood pile. Having damp areas and dry areas and even a little pond can all make a big difference, as well as leaving some parts of your garden to go ’wild’. In fact, some of the best things you can do for insects are also the easiest: let your grass grow tall, and don’t weed too much. Insects will thank you for it!

Scientists in the UK have discovered that some groups of insects, like moths and ladybirds, have declined by up to 70% in recent years, so making your garden insect-friendly has never been more important.

Putting box up

Make your own web

To help see just how important insects are, why not make your own food web? To do this, spend a little time watching wildlife in your garden or local park, and see what’s eating what. Then write it down with lines connecting the different food chains to form a web.

For example, you might see a spider catch a fly, then see a wren catch the spider. You could also write down what you think the fly was eating (maybe some rotting fruit) and what might eat the wren (perhaps a tawny owl). Then go back to the fly and think about what else might have caught it (a house sparrow), what might have eaten the house sparrow (a sparrowhawk) and so on.

The more wildlife you add, the more complex your web will become. See how big you can make yours!

A simple oak woodland food web