Ya she has rats and insects and all sorts with rainy season. She didn't think through the responsibility of a long lease and the realities of living in a place with no proper doors. She makes it look grubby and dirty aswell
Rats are probably in there because of her lifestyle!
They actively search out food sources. Left over containers, pizza boxes etc will attract quickly.
This is hygiene 101. Doesn't happen mice in Ireland because of temp etc. but this behaviour of rats is far more endemic in warmer climates.