Teaching overview

Learning points

  • Having hair or fur is one of the defining features of mammals.
  • Hair or fur is important to mammals because it helps to keep them warm and protects against rain and snow.
  • Some mammals grow a thicker coat of hair during the winter months.

Curriculum keywords

  • Mammal
  • Fur
  • Characteristic

5 things you didn't know

What has hair?

1. Hair is a characteristic of the group of animals called mammals, which includes humans. All mammals have hair at some stage in their lives, while no non-mammals grow hair.

Lifespan of a human hair

2. On average, humans each lose about 50–80 strands of hair every day! These are replaced by new strands, which will grow for 2–6 years before they fall out too.

Keeping warm

3. Some mammals, like the east-Asian Bactrian camel, grow a thicker coat of hair during winter months to keep them warm.

Hairy hedgehogs

4. The spikes of a hedgehog are actually thick, hard hair called quills.

Sea otters

5. Sea otters have more hair than any other animal – as many as 165,000 individual hairs per square centimeter! This helps keep them warm in very cold water.

Spark a discussion

  • What are some of the other defining features of mammals?
  • How would life be different if our human bodies were completely covered in thick hair like many other mammals?
  • Is hair alive?

Twig Science: A Complete Pre-K–8 Program for the NGSS

Immersive Investigations with High-Quality Multimedia

  • Investigating, designing, building, and understanding phenomena
  • Hands-on, digital, video, and print investigations
  • Synchronous/asynchronous distance learning