RACHEL, Nev. — The alien invasion was underway, and David Day wanted no part of it.

Some 3,000 visitors were beaming into his tiny hometown this weekend, snapping selfies outside the secretive Area 51 military test base, running through sagebrush in alien costumes and dancing to throbbing club beats as part of a viral online joke bewitched to life.

Mr. Day pointed to the signs nailed to his front gate in Rachel, Nev., population 40ish (50 on weekends).

GO HOME. NO ALIENSTOCK.

People in this sparsely populated expanse of scrub desert and sun-blasted mountains have gotten used to the conspiracy theorists and U.F.O. chasers who make the two-hour drive from Las Vegas hunting for an extraterrestrial truth behind the secrecy and security of Area 51 — and leave with nothing but an alien tote bag or a roll of little-green-man toilet paper from the souvenir shop.