Exploring how marine mammals stay warm
How do marine mammals keep warm?
Marine mammals like seals, polar bears, and whales have evolved a brilliant solution to surviving in freezing waters – a thick layer of fat beneath their skin called blubber (also known as adipose tissue). This insulating layer covers their entire body, excluding their limbs like fins, flippers, or flukes.
Blubber helps animals in more than one way.
Insulation – Keeps them toasty warm in icy environments
Energy storage – Acts like a built-in pantry for long journeys
Buoyancy – Helps them float effortlessly through the water
Migratory whales rely heavily on their blubber when travelling between nutrient-rich feeding grounds and breeding areas where food is scarce. Whale mothers continue to fast after their calves are born, surviving entirely on the energy stored in their blubber. Talk about dedication!
-WILD FACT TIME-
Bowhead whales have the thickest blubber layer of any marine mammal – up to 19 inches thick!
These incredible creatures live in polar waters and can survive for up to 200 years. Imagine the stories they could tell!
The Blubber Glove Experiment
This hands-on experiment lets curious kids discover exactly how blubber works. By creating their own “blubber glove,” they’ll experience the insulating power of fat first-hand – quite literally!
We made ours using two sandwich bags and vegetable shortening (Trex), then compared it to a single bag with no insulation. The difference? Substantial.
Give little ones time
to explore…
It took Little O a moment to grasp what was happening. He switched between the blubber glove and the regular glove several times, touching the ice with each one. After a few attempts, it clicked – he quickly realised how much warmer the blubber glove kept his hand and didn’t want to stop using it.
A challenge…
It’s quite tricky to pinch or grab ice with the double-layer bag. But that’s part of the discovery.
What you will need
- 3 sandwich bags/small plastic bags
- A bowl or sensory tray
- Bag of ice
- Polar animal figures (optional)
- An old towel or two to catch spills
- (Optional) Science experiment worksheet
Instructions:
- Scoop shortening into one bag and spread it around so it covers the inside surface
- Open this bag and place another bag inside, making sure the shortening surrounds the inner bag completely
- Fill your sensory tray with ice and add polar animal figures if you’re using them
- Place both the blubber glove and a regular bag (without shortening) beside the tray
- Have your child try the regular bag first, placing their hand inside and touching the ice
- Then switch to the blubber glove and feel the difference
What we did:
Setting the scene
I started by showing Little O some quick video clips about polar bears over breakfast. We chatted about how they stay warm in such freezing conditions. Since he has a short attention span, I kept the explanation brief and to the point.
The experiment
Later, I set up a sensory tray at his table filled with ice, polar bear figures, a toy ice float, and both gloves. The animal figures are optional, but for Little O, they helped bring the experiment to life and gave it real context.
I placed each glove next to the ice tray so he could easily switch between them. Little O chose the non-blubber glove first – perfect for comparison!
Top tip:
Little O has small hands, so I used smaller sandwich bags for his blubber glove. I made a second one that’s currently chilling in the fridge, ready for Big O to try when he gets home from school.
Results
As I mentioned, it took Little O a few goes to understand what was happening. Repeating the experiment helped him grasp the concept. Once he realised how much warmer his hand stayed in the blubber glove, he was hooked! The experiment brilliantly demonstrated how that layer of fat keeps marine mammals cosy in freezing waters.
What to do after
After our experiment, we talked about how blubber works to keep polar bears warm. I also explained how other marine mammals – like whales and seals – rely on blubber for insulation too.
Did you know?
International Polar Bear Day is
on 27th February
Polar Bears International founded this day to raise awareness of the increasing struggles and threats polar bears face in our changing world. Find out more and discover how you can help: polarbearsinternational.org/
Extension ideas for older children:
For older or more curious kids, use a science experiment worksheet to record observations, predictions, and results. This develops scientific recording skills and encourages deeper analysis.
You could also explore different insulating materials by creating gloves with:
- Polystyrene packing pieces
- Feathers
- Cotton balls
- Fabric scraps
Which works best? Let the experiments begin!
