Read the following text and choose the correct answer.

    The Island of Wingo is by the island of Singa. In the water around Wingo Island, there are hundreds of sharks. They are so many that the water bubbles like a whirlpool. People can only get to Wingo Island by boat. The boat has a rocket on it. The rocket takes people over the sharks and onto the island.

    Wingo Island has no sand but it has green moss. At night the moss sparkles like stars. Tall stars called Fruji grow everywhere The Fruji tress have purple leaves at the top and yellow fruit all over them. When a fruit falls off, another tree grows in a minute.

    The Weather on Wingo Island is very hot but at twelve o’clock, everyday, it rains. Sometimes, there are windstorms. They happen when too many animals fly around at the same time.

    People who stay on Wingo Island sleep in a big-gloo. It is like an igloo but it is on long poles. It has a ladder to get up and a slide to come down. The big-gloo has a moss bed, chairs, and tables that are made of Fruji tress.

    There is no television on Wingo Island. So is the telephone and computer. It is place to listen to the leaves whispering. It is a place to lie on soft green moss and look at the clouds. It is really a place to dream.

What causes windstorms at Wingo?