School › Camouflage › Ages 10–11
Hide, disguise or warn
Background matching, disruptive patterns, countershading, colour change and warning colours: discover the tricks animals use, then run a fair test to find the hardest colour to spot.
Read
Camouflage is colouring that makes an animal less visible. It helps prey hide from predators, but it also helps predators sneak up on prey: some groupers lie still on the sea floor waiting for food.[1]
Background matching: the animal looks like its surroundings. A fawn's spots blend with the forest floor, a stick insect looks like a twig, and the decorator crab even sticks algae and bits of rubbish onto its shell.[1][2]
Disruptive colouration: spots and stripes break up the outline of the body, so the eye cannot pick out the animal's shape. Tigers, leopards, cheetahs and boa constrictors use it.[1]
Countershading: many animals are darker on top and lighter underneath. Light from above normally makes the top look bright and the belly look shadowed; countershading cancels this, so the animal looks flat and is harder to spot. Many sea animals use it.[1][3]
Changing colour: the snowshoe hare grows a white coat for winter, set off by the shorter days and taking about 70 days. Octopuses and squid change colour in a flash using thousands of tiny bags of colour in their skin, called chromatophores.[6][7][5]
Warning colours and mimicry: bright red, yellow and black warn predators off, like the bad-tasting monarch butterfly. Some harmless animals copy the warning colours of dangerous ones, and some butterflies copy species that taste bad.[1][2]
Try it: Which colour is hardest to find? A fair test
You need
- Paper in four colours (for example green, brown, grey and yellow)
- Scissors
- A ruler
- A patch of lawn or a large printed photo of grass and leaves
- A stopwatch
- A results table
Safety
Use scissors carefully. Check the lawn for nettles, glass and dog mess before you start. Wash your hands afterwards.
What to do
- Cut 5 caterpillars of each colour, all the same size (for example 4 cm by 1 cm): 20 in total.
- Predict which colour will be found least often and write down why.
- One group scatters all 20 caterpillars on the same area of lawn while the 'predators' look away.
- A predator has 30 seconds to pick up as many as possible, one at a time.
- Count how many of each colour were found, put them back and repeat with two different predators.
- Add up the results. Which colour 'survived' best? Is the test fair?
What happens, and why?
Caterpillars that match the background survive best, because they are harder for the eye to separate from the grass and leaves. To be a fair test, only the colour may change: same size, same area, same time and several different predators. Scientists run similar tests outdoors with paper prey and real birds, for example paper caterpillars with a mealworm inside on bramble bushes, or artificial moths on tree trunks.[3][4]
Play: Which trick?
Each animal uses one main camouflage trick. Sort them into the right group.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 6–7 · Ages 15–16