Children ask questions – and we have the answers. This time: why is it warmer inside igloos than outside, and how can you tell the difference between a fir tree and a spruce tree (note: this is particularly important at Christmas)?

Why is it warm inside an igloo?

Igloos are made of snow. But these little snow houses still manage to provide protection from the icy cold. Inuit, as the indigenous people of the Arctic Circle are called, still use igloos these days as shelters – when they’re out on long hunting trips, for example. Inside an igloo is nowhere near as warm as in a heated house, but still much more comfortable than outside. This is because the compacted snow used to build an igloo insulates very well, which means it lets the air inside the igloo build up, and therefore warm up. But it’s never warmer than 5 degrees even inside the best igloo, either.

What is the difference between a spruce tree and a fir tree?

It’s actually fairly easy to tell apart the two best-known conifers which grow in our woods. There’s a saying to help: “The spruce will prick you, not the fir”: fir needles feel fairly soft to touch, whilst spruce are harder and bristly. And the trees’ cones are also completely different. Spruce cones are long and scaly. They often lie on the forest floor, whilst fir trees don’t normally lose their cones. Fir cones are also rounder and upright on their branches. And that’s another big difference: spruce cones hang down from the branches.