Invertebrates in Animals - Living Things | Grade 6 Science

- Invertebrates are animals without backbone.
- Animals with backbones are called vertebrates.
- Examples of invertebrates include insects such as a housefly, arachnids such as a spider, millipedes, and centipedes.

Insects

Observe the picture below of an insect:

Characteristics of Insects

• Insects have six legs (three pairs)
• Insects have three body parts (head, thorax and abdomen).
• Insects have compound eyes.
• Some insects like housefly have wings while others like ants have none.
• Insects have a pair of antennae on their head.
• Insects lay eggs.
• Insects include: ants, housefly, locusts, butterfly.

Arachnids

- Examples are ticks and spiders

Characteristics of Arachnids

• They have 8 legs, four pairs.
• They have a soft body.
• They do not have wings.
• They do not have antennae.
• They have their body divided into two: (Cephalothorax and Abdomen)

Millipedes and centipedes

Characteristics of Millipedes and centipedes

- The following are some characteristics of millipedes and centipedes.

• They have many legs.
• They have segmented bodies.
• They have antennae.
• They have hard outer cover.
• Millipedes have two pair of legs per segment.
• Centipedes have one pair of legs in a segment.

Note: Centipedes can bite and sting which can cause the skin to turn red due to their venom.

Importance of invertebrates to human beings

1. Insects are used to pass pollen grains from one flower to another.
2. Some insects such as bees provide honey which is food for human beings.
3. Millipede and centipede are important in soil formation. They also help to aerate the soil.
4. Insects such as silkworm produce silk used in making clothes