Have you ever wondered how animals stay warm in the winter? Lots of animals grow extra fur to help keep their bodies warm, but most animals also put on extra fat during the fall that helps them stay warm all winter long. How does fat help keep them warm? Do this experiment to find out!
The layer of Vaseline or shortening that you surrounded your hand with acted very similar to a layer of fat that animals grow for the winter. It protected your hand from the ice water and you were probably able to keep your covered hand in the water for longer than you could stand to keep your bare hand in! How did the Vaseline or shortening protect your hand, though? It insulated it from the cold water. This means that it kept the heat that your hand already had from escaping into the water and also blocked the cold temperature of the water from touching your hand as quickly. Your bare hand did not have this extra layer of protection and all the heat from that hand was transferred to the water almost right away. Then it only took a few seconds for the cold from the water to start making your hand feel very cold. Animals grow a layer of fat underneath their skin or fur that helps insulate them from cold weather, just like the layer of Vaseline did for your hand!
What is the best way to stay warm outside on a cold day? Try these ideas and then decide which one works best! Go outside on a cold day and try each activity. Make sure you are wearing warm enough clothes to protect you from the cold, but you don't need to put on extra clothes to try to keep yourself even warmer than normal - just dress the way you would if you were going to go for a walk or to play outside.
Which activities kept you the warmest? Which ones made you the coldest? Which ones used the most energy (made you most tired)? Which ones used the least energy (didn't require you to do anything or didn't make you tired)?
When you sit very still and don't move much, it is harder for your body to keep its natural heat. When you run around or move your muscles, it helps your blood flow through your veins better and keeps you warmer for longer. However, running around or using up a lot of energy will also make you tired faster. Wind also makes you get colder faster because it blows the warm air that is around your body away from you. If you are huddled up you will be warmer than if you are just sitting or standing, because more of your body heat is kept close to you for a longer time (the wind can't blow it away as fast). Now that you know a little bit about body heat, wind, and energy and how they work to keep you warm or make you cold, can you think of the best way for animals to keep warm during the winter? Where should they go to sleep? Should they group together?
How do animals find food in the winter? Sometimes it can be pretty hard. Do this activity to find out what it would be like if you had to eat food that was frozen or covered by ice!
Before you froze the fruit, you could probably smell it without trying very hard. After you covered the fruit with water and froze it, it was much harder to smell the fruit. That is because the water surrounded the fruit and then froze, which trapped the scent inside the ice. It also sort of watered down the smell of the fruit, making it harder for you to smell. The same thing happens to food in the wild after it freezes or when snow and ice cover the ground, branches, and berries. Snow makes it hard to animals to see their food and ice makes it hard for them to smell it and eat it. This is one of the reasons that a lot of animals collect food in the fall and store it someplace dry to eat during the winter when food will be harder to find! Because of the cold weather, there is also less food available, even for the animals that could find it. That is because most plants lose their leaves and stop producing fruit and go dormantso that they can also survive the winter!