Why do blue-tongue lizards stick out their tongues?
Quick answer from Eartha
A blue-tongue lizard sticks out its bright blue tongue to scare off danger! Most predators have never seen such a strange, glowing colour, so the surprise can make them pause or back away. The lizard also hisses and puffs up its body at the same time, making itself look bigger and bolder than it really is.
The longer story
Blue-tongue lizards are usually slow, calm reptiles that would rather bluff than fight. Their bright blue tongue is their best trick, because almost nothing else in the bush looks like it.
When a bird, snake, or curious pet gets too close, the lizard opens its mouth wide and flashes its tongue while hissing loudly. This sudden flash of colour and sound can startle a predator just long enough for the lizard to escape or be left alone.
Scientists have found that the tongue reflects ultraviolet light, which some predators like birds can see even better than we can, making the warning flash even more noticeable to them.
Blue-tongue lizards also rely on camouflage the rest of the time, with brown and grey stripes that blend into leaf litter, so the blue tongue is normally kept hidden until it is really needed.
Try this at home: surprise colour test
- Hide a brightly coloured object, like a blue toy, under a plain cloth.
- Ask a family member to look away, then suddenly reveal the bright colour.
- Talk about how a surprising flash of colour grabs attention, just like a blue tongue.
Words to know
- Camouflage
- Colours or patterns that help an animal blend into its surroundings.
- Ultraviolet light
- A type of light some animals can see that humans cannot.
For grown-ups: what is my child learning here?
Age band: Ages 7-11
Curriculum link: Australian Curriculum v9 Science, Year 3 — living things have external features and behaviours that help them survive in their environment.
The concept: Children learn that behaviour, such as displaying colour, can be a defence strategy separate from camouflage.
More classroom ideas are on our teachers page, and safety notes for families are on for parents.
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