The Three Little Pigs built houses of straw, sticks, and bricks. But that's probably because they didn't live in an arctic environment. If they had, they probably would've built a house out of snow and ice. We wonder how an igloo would stand up to the Big Bad Wolf…

People in different parts of the world build different types of houses, because people tend to use materials that are plentiful in their area. For example, wood and stone are plentiful in some areas of the world, so wood and stone houses are popular in those areas.

In areas with extreme weather, however, building materials may be scarce or nonexistent. In Alaska and the frigid areas of the Canadian tundra, for example, good building materials can be hard to find. Instead, the native people who live in these areas — called the Inuit or Eskimos — use something that is plentiful in their area: snow.

The Inuit call their homes iglu, which is where the term “igloo" for “snow house" comes from. First built by hunters to survive in extreme cold weather conditions, igloos have been around for thousands of years.

Your mental image of an igloo may have come from cartoons on television, but it's probably fairly accurate. Many igloos are simple dome-shaped structures made entirely of blocks of snow and ice.

Igloos can come in a wide variety of shapes and sizes, though. There's no one way to build an igloo and the number of blocks used to build one will vary with the size of the igloo and the builder's design.

Some igloos are designed to house one person while hunting in the wild, while others may house a small village of people through interconnected igloos with ceremonial rooms and attached corridors and walls.

Some of you may think it's a bit strange for people living in extreme cold to build a shelter out of snow and ice. After all, snow and ice are extremely cold themselves, right? Believe it or not, though, igloos can be very comfortable to live in.

An igloo's walls block the icy wind that's common in these areas. Snow also happens to be a very good insulator. This means that the heat inside the igloo — whether from a small oil lamp or just body heat — tends to stay inside the igloo. The result is that the inside of an igloo can be as much as 40 degrees (Farenheit) warmer than the outside temperature.

Igloos also get stronger and warmer over several days after they're first built. As trapped heat causes the inside of an igloo to melt slightly, the melted snow will then refreeze when the igloo is unoccupied. A few days of this thawing/refreezing cycle will eventually turn the entire structure to solid ice, which is even stronger and warmer than the original structure.

Snow also happens to be an easy material to work with when building an igloo. The arctic winds pack it together tightly, which makes it very sturdy. Yet it's also lightweight and easy to cut into blocks to build an igloo.

An experienced igloo builder can construct an igloo in about an hour. If you've never built an igloo before, it'll probably take you three to six hours or more. All you need, though, is plenty of packed snow, a few tools and patience.

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We can’t remember what tomorrow’s Wonder of the Day is about. We should’ve written ourselves a note!