Snuggly Science: How Puppies Keep Warm
Have you ever woken up on a cold, frosty morning and just wanted to snuggle down deeper under the covers? Animals, like puppies and piglets, do not like being cold either, but they do not have hands or blankets to wrap themselves up. So when animals get chilled, they change their behavior and do things like huddle – they curl up close to other animals. In this science activity, you’ll see just how much huddling can help reduce heat loss.
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Want makes a puppy want to sleep in an adorable heap? Snuggling, also known as huddling, does more than create cute puppy piles. Puppies, like other animals, huddle to keep warm. Heat is constantly flowing into and out of everything around you. Just as a ball rolls downhill, heat “rolls downhill” too, flowing from an object that’s hotter to one that’s colder. If, for instance, you put a cup of hot chocolate in a room-temperature room, the heat will flow from the hot chocolate to the room, cup and table. These surroundings will actually warm up from the hot chocolate’s heat. When the temperature of the hot chocolate cools down enough to reach the surrounding temperature, the heat flow stops.
Heat flows from a hotter object to a colder object in several different ways. For example, when puppies are huddling together to keep warm, they are reducing the amount of their bodies (specifically surface area) that is exposed to the colder open air, and so are reducing heat loss in two ways: by radiation and convection. A puppy also gains heat by another way – conduction – if the puppy it’s snuggled up to happens to be warmer.
Extra: Try repeating this activity but compare three jars touching to two jars touching or to three jars separated by an inch. How does the heat loss compare between these different configurations and to one jar alone?
Extra: Think of how you could add “fur” or “fat” to your puppy models in this activity and then try it out. How do these additions affect heat loss?
Extra: You could investigate increased heat loss through convection by blowing a fan on the jars. How does this affect how much heat is lost over time?
Observations and Results
Did the three jars huddled together lose less heat over time compared to the one jar alone? Was their difference in temperature the greatest at the end of the ten minute period?
Over time, you should have seen that the water in the jars – alone and in a huddled group of three – lost heat, but the jar alone lost heat faster than the three jars huddled together. The temperature of the water in the jars should have started out at about 190 degrees Fahrenheit, since this was the temperature immediately when they were removed from the pot. As just one example, the temperature of the water in the one jar alone may have then dropped to about 172 degrees Fahrenheit after ten minutes, while the temperature of the water in a jar huddled in a group of three may have only dropped to about 176 degrees Fahrenheit. (The exact size and shape of the jars affects how quickly they lose heat, as a larger amount of hot water will take a longer amount of time to cool down compared to a smaller amount of the same-temperature water, and the shape of the jars affects their total surface area.) When the jars are close together, just like puppies snuggling together, they help keep each other warm, primarily through conduction.
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Teisha Rowland, PhD, Science Buddies
Science Buddies |
Heat, temperature, warm-blooded animals
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