I'm Telling You, They're Aliens! By Jeremy Strong

Rob worries about everything - being bitten by snakes to dinosaurs waiting
round the corner. So when the Vorks move in across the road, he is convinced
that they're aliens and that he must save the world!

About the Author
Jeremy Strong is immensely popular with children, particularly boys, who love
his unique brand of silliness. He won the Children's Book Award in 1997 with
The Hundred-Mile-An-Hour Dog, and his books about Sigurd the Viking were made
into a TV serial."