Strange, strange issue inside my car?

hi everyone, i have a strange issue here, everything is fine with my car, until a week passed and i noticed a mouse/rat sneek out from underneath the car, i didn't pay any heed to it since the area i live in, it's kinda bad, a lot of dirt and a lot of mice and stuff wander. what is wierd is that i checked my car today for its oil and water and found a rat sitting on the gear box, i yelled and the hood came on my head... now i know the engine bay is open from underneath since i have a 92 swift, is there anyway i can get rid of this problem? i park my car under my place, its an appartment, i tried parking it a bit away but still the same until i had to ask you guys, i don't wanna park my car away too much since its risky, really upset. please suggest