Forced baby sitting

Just moved in with a friend and she’s literally never home. Gone from 7 a.m til 12 or 1 a.m and leaves her children here (12 & 9 & 5 year old niece). Her children are extremely hard headed and rude. She said I don’t have to baby sit. But , I am by default because she’s never here and they’re always bugging me asking for food and wanting to go with me every time I try to go out to get away from them. They’re always hungry and all she bought was snacks because she’s never here to actually cook anything. And her son has literally always going through my stuff in my closet, like taking out my pillows and laying on them (which I hate because he doesn’t like to bathe and his clothes are often smelling like ass). And it’s roach infested

She doesn’t really say anything. And I bought a new door knob with a lock on it to keep her son out because she basically said he’s going to go through it no matter what. Which is true because she’s never here to enforce any rules. They do what they want