5.4 Animals save us

Earthquakes - the name of this natural phenomenon says it all: it is a sudden and quick tremor of the Earth's surface.

When an earthquake happens under water, it can cause a tsunami, a large wave of water that is very powerful and can destroy everything in its way.

An underwater volcanic eruption can also cause a tsunami. When volcanoes erupt on land, their ash and hot lava can cause a lot of damage.

They can also cause fires, although fires, unfortunately, are most often caused by careless people.

Fires usually happen during dry periods in summer, when everybody looks to the sky hoping for rain. Heavy rain and lightning form thunderstorms. They can be very dangerous because they can cause floods. Floods happen when the land can't absorb all the water from rain, or even from snow that starts to melt in spring.

Dogs are man's best friends, that's for sure, but they play a very important role in saving people's lives.

They can be trained to do a lot of different tricks but the most important and valuable skill they can learn is saving people's lives. Everybody knows that a dog's nose functions much better than ours. How's that? Let's use some numbers to explain. A dog's nose has up to 300 million receptors, whereas people only have about 6 million. And the part of their brain responsible for smell is 40 times larger than ours. A dog's nose has two functions - one for smell and one for breathing. This is why they can smell different scents at the same time.

Dogs can smell up to 100,000 times better than humans. This is why search-and-rescue dogs can find people under earthquake rubble or under avalanches – these are masses of snow that fall very fast from the top of mountains.

The police use them to track criminals, search buildings, or sniff out illegal materials like drugs, weapons and bombs - in cars or in luggage at airports.

This is Ray, who is eleven, with his dog Olivia. Olivia is an assistance dog trained to help a person in a wheelchair. If Ray falls from his wheelchair, she can bring a blanket, so he doesn't get cold. She can also bring a mobile phone so he can call for help. Ray says the most important thing that Olivia gives him is his independence. She helps him when he goes to school or to a birthday party so his parents don't have to come with him, and he can be alone with his friends.

This is Eppo. He is a guide dog for the blind. The blind use a white cane to help them walk but dogs can also assist. Eppo helps his owner Carol, who is 25, to move around and handle everyday tasks. He can open the door for her or pick up a thing that she drops. He can even turn the lights or the washing machine on or off. The most valuable thing for her is that, with him, she can live on her own. If there's an emergency, he knows how to press an alarm button.