"The Very Foreign Exchange Family"

It's a race to save the Earth, but from what or whom? The Lloyd family is deeply troubled by terrifying 'dreams' about alien creatures and mystified by a strange configuration on their back lawn. Soon their government recruits them to host a foreign-exchange family, which is considerably more foreign than anticipated. The aliens have come to rescue the Earth from a castastrophic environmental disaster. Secrecy is essential so the aliens can work without distractions. However, the Lloyds have an obsessively nosy neighbor who is exceptionally resourceful in spying on her neighbors. Can the Lloyds keep the real identity of their alien guests a secret? Why are fifty gargantuan heavily armed spaceships speeding across the galaxy towards the blue planet? The aliens have a horrifying secret. Will the Lloyds find out in time to save the Earth? Can a ten-year old boy and his hamster save the planet?