Odd One Out

The drinks menu

Activity overview

15 mins
Ages 9 – 11

Science topics:

States of matter , Evolution and inheritance , Topical science

Put your class’ observation skills to the test with these three thirsty animals. This activity is great for promoting observation and discussion skills.

Run the activity

1. Show the three images above and ask everyone to come up with as many similarities and differences as they can. If they get stuck, prompt them to think about:

  • appearance
  • what they do
  • where they might be found

2. Then, everyone needs to decide which one is the odd one out and why. Encourage a reason for every answer and there is no wrong answer!

Background science

We can see a ladybird taking a drink and two thirsty desert dwelling creatures: the Bactrian camel and a fog basking beetle.

Animals need water to survive. Water is found on Earth’s surface in all three states: liquid, solid and gas.  Of course, ice, snow and water vapour can all be changed into liquid water because changes of state are reversible. We are most familiar with animals that drink liquid water, including the ladybird. Other animals live in extreme environments where it is too hot or too cold to find much liquid water. Some of these animals have adaptations (special features or behaviours) that help them change ice, snow or water vapour into liquid water that they can drink.

Bactrian camels are distinctive because they have two humps (made of energy-rich fat, not water!). They live in the harsh Gobi Desert of Mongilia and China where temperatures range between -40°C to 40°C. In the winter months, the camels can quench their thirst by eating snow. Only a few animals can do this without dangerously lowering their body temperature.

Meanwhile, the average rainfall in the Namib Desert is just 1 cm per year, making it one of the driest habitats on Earth. Fog-basking beetles have adaptations that allow them to harvest water vapour from the air. In the early morning, they climb sand dunes and stand with their bottoms higher than their heads. This puts them in the path of fog rolling in from the Atlantic Ocean. Tiny drops of water condense on the bumps on their wing cases, before rolling down the grooves towards the beetle’s mouth.

Watch out for... Some children who may think that living things can make changes to their bodies to help them survive in their environment. This is not the case; adaptations occur over many generations when a mutation may give an animal or plant an advantage which makes it more likely to survive than others.. This does not need to be corrected during the session, but you can pick it up later. 

Take it further


Your class might like to attract ladybirds to the school grounds: find out how to make a ladybird lodge.

You could ask the children to research the other adaptations of the Bactrian camel. This website and this link are good starting points. You could also discuss the pros and cons of melting snow or ice to drink. Why do they think mountaineers climbing Everest always melt snow and boil it before drinking? (To kill microbes). Try our What if an astronaut gets thirsty? to discuss how reversible changes might help astronauts to get drinking water in space.

Ask the class to discuss where their own drinking water comes from. Anglian Water and Thames Water offer primary resources you may want to use. Many people around the world do not have such easy access to clean water. Explore what this might be like using this 360°C photo or with Wateraid's KS2 resources or Practical Action's Water! Water! resource. How do they think global warming will effect access to water in different countries?


Watch the Bactrian camel eating snow (with David Attenborough commentary) here.

This BBC clip shows us fog-basking beetles in action and this short bbc video explains how humans might try and copy the fog basking beetles. Already the design of the dew bank bottle has been inspired by the amazing insects.

Image credits:

Erdenebayar Bayansan via Pixabay CC0

Skeeke via Pixabay CC0

eye-ad via Pixabay 

GbbIT via Wikimedia