1 Ishmael: You’re here to abduct Earth women??
2 Martian 1: Well, I mean, what else does your puny planet have to offer?
3 Martian 1: Water? Ha ha ha ha!!
4 Martian 2: Actually, we could use some of that.
4 Martian 1: Shhhh!!!

Traditionally in Martian invasion fiction, there are several things that Mars needs:

1. Water
2. Earth women
3. Explorers
4. Heroes
5. Mechanics
6. Moms - although this may be subsumed by 2
7. Lovers
8. You!
9. Chickens
10. Lupulin
11. Moscato
12. Malbec
13. Shiraz
14. Guitars!

The first two are generally the most important, though.