Teach Primary 18.8

• What does the animal look like? • Which of the Big Five could it be? • How is it adapted to survive in moss when it dries out or when it freezes? moss by curling up when the moss is drying. When it is freezing, they grow a thicker skin, like a sleeping bag, to sleep in until conditions improve. The rotifer is known as a wheel animal because when it feeds or swims it uses two large organs on its head that look like spinning wheels. It is adapted to live in moss by being able to shrink into a protective ball and sleeping when it is too dry or too cold. When normal conditions return, the rotifer wakes up. The tardigrade , also known as the water bear, is a sausage shape with eight stubby legs, a wrinkled face with a pig-like snout and long claws at the end of each leg. It is a pale or red colour. microscope will magnify the animals. A magnification of ×20 or ×40 will allow you to see these creatures. As you spot each animal, discuss its characteristics and adaptations with the children. The moss mite has a dark round body, a small head and eight hairy legs. Some people say it looks a bit like a beetle. Moss mites have a thick exoskeleton to help them keep water in their bodies. When conditions get too dry or too cold, they move away and hide in soil or crevices. The nematode is a long, thin and often wiggling worm. They are often called thread worms. Nematodes appear pale or transparent and are adapted to living in • When looking at the moss-squeeze, there are a lot of objects on the slide. What clues could tell us if an object is living, non-living, or dead? How might you record and display the number of objects in each category? • Using the information provided during the lesson, design a key to help identify the Big Five animals. • Write a story of how one of the Big Five animals survives in a moss cushion over a year. • Make a map of the school grounds and mark on it all the places moss is found. • Lots more resources, including worksheets and a slideshow all about adaptation, are available for free on the Moss Safari website (mosssafari.com ). EXTENDING THE LESSON Tardigrades, too, can curl up into a tight ball when their habitat is dry or freezing, and wake up when conditions improve. The gastrotrich looks like a hairy worm. In fact, its name means ‘hairy belly.’ It is the smallest of the Big Five. It glides around using the hairs on its body to swim, and has a forked tail. Gastrotrichs cannot survive drying out or being frozen, so instead they lay eggs that are adapted to withstand these conditions. The eggs hatch when the conditions get better. 3 | THE MICROSCOPIC SAFARI Once the children have been introduced to what they are looking for, send them on the Moss Safari using a microscope to scan the dish or microscope slide in search for the Big Five. Alternatively, if you have a camera attached to your microscope, you can project the Moss Safari onto a large screen. Go on a Moss Safari together, stopping at the Big Five, describing them, identifying them and talking about how they are adapted to deal with drying out or freezing. Encourage children to record what they find, and justify their identification. Visit tinyurl.com/ tp-Moss to download identification sheets. Dr Andy Chandler-Grevatt is a senior lecturer in science education at the University of Brighton, he founded Moss Safari and does outreach to promote microscopes and inspire future scientists. “You’ll need to look out for five animals that are less than a millimetre in length” USEFUL QUESTIONS www.teachwire.net | 95