Do villagers move out randomly or is there a reason?

[KnoxUK]

I had Yuka move in for 2 days then she decided she wanted to go. Is this random? It just seemed very odd how she was really happy to be apart of the island one day, then the next she wanted out :S

 

[Dormire]

It's very random but the prompts usually occur at least every 2 weeks so...yea.

 

[dino]

it doesn't mean anything personal, op ! you're doing fine and ahe probably loes your town. its completely random. people have tried everything to pin down a logic to who moves and there truly is none lol.