Minibeasts are simply small animals: spiders, snails, slugs, beetles, centipedes, worms, earwigs, caterpillars – and thousands of other types of minibeast that exist all over the world. Officially, minibeasts are called invertebrates, which are animals without a backbone, and these are the most numerous type of animal in the world. In Britain alone there are over 25,000 species of known invertebrates. Unlike vertebrates (animals with a backbone), they do not have a skeleton inside. This makes them soft and bendy, and because of this, some of them have hard shells to live in. Some, like insects and spiders, have a thin, strong outside covering called an exoskeleton - this means they have protection for their bodies. They also have legs, and often wings, which let them move more quickly and easily than other minibeasts.
The term minibeasts is a useful lay term to employ when generally describing a broad group of small animals. However, it is more scientifically accurate to classify many minibeasts as arthropods.
There are many different types of arthropods, including:
- Insects – including bees, butterflies, beetles, ants, moths, praying mantis, cicadas, cockroaches, fleas, wasps and flies
- Arachnids – including spiders, scorpions, ticks and mites
- Myriapods – including centipedes and millipedes
- Crustaceans – including crabs, shrimps, prawns, lobsters and crayfish
Insects have six jointed legs and a body that is divided into three parts: head, thorax and abdomen. An insect’s head has a pair of antennae and mouthparts that are adapted for particular diets. 75 per cent of all animal species described by scientists are insects.
Arachnids (spiders, scorpions, mites and ticks)
Arachnids have a body divided into two parts: the cephalthorax (head and thorax) and the abdomen. They have four pairs of walking legs and lack both antennae and wings. They usually have eight eyes. Spiders are arachnids that have jaws with fangs that inject poison, and they possess silk glands and spinnerets on the abdomen. Scorpions, mites and ticks are also part of the arachnid family. Scorpions have a long tail that ends in a stinger. They also have a pair of pedipalps (front limbs) that end in grasping pincers at the front of their bodies.
Centipedes and millipedes
Most centipedes have 20-30 pairs of legs. Very few have as many as 100 legs. Centipedes are carnivores that catch other invertebrates for food. They have fangs, which inject venom into their prey. Large centipedes may sometimes even eat vertebrates such as frog or mice. Millipedes, on the other hand, are herbivores. They feed on vegetable matter and are found in moist places such as under logs. They have hundreds of tiny legs that move together in waves to carry the millipede along.
Crustaceans (crabs, shrimps and slaters)
All crustaceans have a body divided into a head, thorax and abdomen, and have more than eight legs. Most of them have a harder section protecting the thorax, called a ‘carapace’. Many crustaceans live in water (both fresh and saltwater).
Where do minibeasts live?
Minibeasts can be found in almost every part of the world. They can survive in the most extreme ecosystems, and in the UK can be found in almost every different habitat.
What do minibeasts eat?
Many invertebrates eat only plants, and they, like all plant eating animals, are called herbivores. Many eat a wide range of plant food, especially leaves, but some feed on only fruit, nectar or pollen. Molluscs (such as slugs and snails) and insects are only classes of invertebrates that have developed mouthparts capable of grinding up green leaves. Grasshoppers and caterpillars have mouthparts with very sharp edges for cutting into leaves. Slugs and snails have a very efficient rasping organ called a radula, which tears up plant food. Herbivorous minibeasts have to keep a watchful eye out for meat-eating minibeasts – the carnivores. Although they are small, carnivorous minibeasts can be ferocious predators.
Why are minibeasts so important?
Some people regard most ‘creepy crawlies’ simply as ugly nuisances and, indeed, some of them can be pests and spread diseases. However, all invertebrates are a very important part of life in the habitat in which they live. For example, in a woodland habitat, invertebrates can be found everywhere, from the floor to the tops of trees, and they are a very important source of food for lots of different mammals and birds. Another important task minibeasts carry out is to act as decomposers. Some minibeasts live in what is called the leaf litter (the layers of leaves that fall to the ground). The minibeasts will eat the dead leaves, animal droppings, and even dead animals. They are the world’s best cleaners.
Many mininbeasts either hibernate or spend the winter as eggs or pupae, so the best time of year to go out and study these creatures is when the weather is warm, from late spring into the summer. Minibeasts, particularly insects, can be found almost anywhere. You will be able to observe butterflies, bees, wasps, other small insects and some spiders simply by watching flowering plants in the garden. Another good minibeast habitat is a pond and the best way to find out about the minibeasts in a pond is to use a net, a large bowl, a magnifying glass and a notebook. Remember to return all the animals to the water when you have finished.
Fascinating minibeast facts
1. Cockroaches can live for nine days without their heads.
2. African cicadas can make a noise as loud as a car horn.
3. The longest insect is the giant stick insect, which can grow to more than 50cm.
4. On an equal weight basis, spider silk is twice as strong as steel.
5. A jumping spider can jump up to 25 times its own body length.
6. Honey bees’ wings beat 11,400 times a minute.
7. The housefly beats its wings over 20,000 times a minute.
8. Ants can lift 20 times their own body weight.
9. Adults cannot chew and swallow solid food. They rely on juice, which they squeeze from pieces of food.
10. The animal responsible for the most human deaths worldwide is the mosquito.
Teaching about minibeasts
To support the teaching of this fascinating topic, download the series of cross curriculum project plans below. These comprehensive resources provide an array of background notes, mini project plans, photo pages and activity sheets. Projects include: minibeast symmetry, metamorphosis mobile and minibeast puppets.
Download Minibeasts Project Plans:
- Literacy Project 1: Dictionary Work (Key Stage 2)
- Literacy Project 2: Limericks (Key Stage 2+)
- Literacy Project 3: Letter Writing (Key Stages 1 and 2)
- Literacy Project 4: Notes and Sentences (Key Stage2)
- Literacy Project 5: Fact Sheets (Key Stage 2+)
- Literacy Project 6: Ugly Bug Ball (All Key Stages)
- Literacy Project 7: Butterfly Books (All Key Stages)
- Literacy Project 1: Ladybird Maths (Foundation and Key Stage 1+)
- Literacy Project 2: Minibeasts Data (Key Stages 1 and 2
- Literacy Project 3: Pond Maths (Key Stages 1 and 2)
- Literacy Project 4: Measuring Minibeasts (Key Stage 2+)
- Literacy Project 5: Minibeast Symmetry (Key Stage 2+)
- Literacy Project 6: Shapely Scorpions (Key Stage 2+)
- Science Project 1: Metamorphosis Mobile (Key Stage 1)
- Science Project 2: Horrid Habitats (Key Stage 2+)
- Science Project 3: Food to Grow On (Key Stage 2)
- Geography Project 1: Terrific Termites (Key Stage 2)
- Art and Design Project 1: Minibeast Inkblots (Foundation and Key Stage 1)
- Art and Design Project 2: Minibeast Puppets (Key Stage 1 and 2)
- Design and Technology Project 1: Revolting Recipes (All Key Stages)
- Design and Technology Project 2: Scorpion Spinners (Key Stages 1 and 2)