There are a couple of reasons why they could be staring at you.
Reason 1: They're rude bullies and are talking crap about you, and they're like: "Oh, is that the girl Kate was gossiping about? She's so weird!". I get that a lot.
Reason 2: They're lesbians who have a crush on you.
Reason 3: They don't have a crush on you, but they still think you're pretty and are admiring you. Still, one or two might be lesbians, though.
Reason 4: Culture shock.
Reason 5: They could be just daydreaming.
Reason 6: You're secretly an alien, but you don't know it and you have hidden tentacles, and sometimes they randomly sprout and people see.
Reason 7: There's a Staring-At-People club and you're the person of choice.
Reason 8: They know a lot of dudes like you and are jealous.
Hope I helped! :)