Year 2 Science Club
Have you ever wondered why some animals have spots, stripes or certain markings? Sometimes an animal's colours can be the difference between life and death as they often use them to blend into the environment. This is called camouflage. Look at the pictures in the slide show. The children were pretending to be birds looking for prey (insects etc.) Would you rather be the brown prey or the brightly coloured prey? Which do you think is more likely to survive and keep reproducing?
But don't be fooled - some animals use their markings to warn prey off. Have you ever seen a red and black frog, or a bright yellow and black frog, perhaps it has stripes or distinct blobs of pattern. These are poison dart frogs and they use aposematism (warning colours) to protect themselves. can you think of any other animals that use camouflage or aposematism to protect themselves?
The children cut out and decorated lizards, spiders and ladybirds. On the back they stuck two pieces of a straw and threaded some wool through, then tied a bead at each end. They hung the crawlies over a door handle and watched with amazement as the crawlies 'climbed' up the wool.
When they pulled the threads, they pressed against the inside of the straws. This created a force called friction that stopped the two things from sliding past each other. When the children let go of the threads, they stopped pressing against the straws, so there was less friction and the crawlies slid back down. Can you explain which force makes the crawlies slide down?
The children put some spots of felt tip pen onto filter paper and then dropped some water onto the ink. Although you cannot tell, each felt tip pen is made from several different colours. When water touches the ink it dissolves and spreads out. This separates the colours and you can see which colours each felt tip is made from. Year 2 also put a spot of permanent ink onto the filter paper. Can you spot it? Can you explain why the ink did not separate?
Year 2 cut out spiral snakes and balanced them on straws.
Everything on Earth is pulled down to the ground by gravity. As the snake is pulled down, its weight is spread evenly around a point called its centre of gravity. This point is below its head, within the space formed by its body. When the children rested the snake on the straw, it balanced perfectly around its centre of gravity. The children predicted what would happen if they tried to balance the snake further along its body. Can you guess what happened when they tried it?