The aliens need to use earth's satellites so that they can coordinate their invasion efforts.
They don't need water
Aliens may not have even built them. Although, if they did why would they, let alone use metal?
Basically one is provided with legs and you can use these to travel round the Earth, apart from the stretches of water where you have to get a boat and row.
Yes
Reptoid aliens are aliens that are green and slimy. They usually collect samples of sheep blood. People think they use sheep blood as a resource, but no. Some fear that one day, Reptoid aliens might control our planet and turn the human race into slavery.
Depends if they can cloak their ships or if they can use stealth or not. Etc etc.
Aliens are not real, there for this is un-answerable.
I don't think there is a word for aliens living on Earth. I think they would just be called aliens.m 2nd Answer: I THINK your question was "What do aliens call Earth people?" There is no evidence to suggest that aliens (other than those coming across the borders of Mexico and Canada) have visited Earth. That being so, it is impossible to know what term an alien would use for Earthlings. An alien's speech probably would be nothing like ours . . . it could be clicks, stomach rumblings, or perhaps not even use sound! :-)
it make a wave that is send to outer space and its calls aliens to come to earth
So far as is know there are no aliens.
Crolustius Guns