Everyone feels cold sometimes, but how do animals stop getting too cold in the winter?

These activities help your students explore how birds and whales keep warm.

Each group of students needs to cut out a number of feather shapes from paper. They can fluff up the feathers by wrapping each feather around a pencil and sliding it off. The feathers should be a curled. The students should fill a plastic bag with the feathers and secure the end. The bag of feathers can be placed on some ice from the freezer, or snow if you’ve got some, and students should place a hand on the bag. What does it feel like? Can they feel the cold? Squash the air out of the bag until the paper feathers lie flat and try again.

Why is it that in the first case the students do not feel the cold, but when the feathers lie flat they can? Can your students work out the difference between the two?

The curled feathers trap air and the air acts as an insulator. Birds fluff up their feathers in winter to provide insulation against the cold. You could encourage your students to think about other things that trap air to keep things warm, such as woolly jumpers and hats.

If you don’t have access to snow or ice, you can try testing the feathers using a radiator to see if you can feel the heat. Be careful no one gets burned.

Whales use a very different method of insulation. This experiment is really messy but works well. Students should make themselves a glove of lard.

Place one hand in a plastic bag and seal it around the wrist. Half fill another plastic bag with lard, and fit this second bag around the first, getting help to secure it in place. There should be a thick layer of lard around the hand. Now place the hand in a bowl of cold water. The lard should act as insulation against the cold, and the student should not feel a thing.