Can I get a little common sense?

I keep getting the winners in my house. Zack has been here for a couple of months. My guy won't stop griping about him.
Apparently, he pees in the backyard. I know he isn't the only one doing it. He does not clean up after his dog, his guests, or his guest's dog. He has an air conditioner that runs all day. When I go outside in the morning, there is a pile of cigarette butts on the table and several beer cans. This is every morning.
I have the second room mate. I knew he was going to be a bit inconsiderate. He was asking if the groceries are shared and that he likes the milk. Instantly, my foot is down on the food. Buy your own food. I know he was already in my lunch food because I saw a wrapper from my food in the garbage can in the bathroom. He was already using Paul's bathroom soap. Um, hello, training for a new job and paying for a house, I cannot afford to pay for yet another mouth to feed. He also thought he would use the detergent without asking first. He asked after he used it.
Does it even hurt anyone to ask to use something first? What the hell is up with people. In my whole life of renting from people, I never had this problem. Except for the guy burning in hell who used my phone without asking. Oh yes, someone else giving my things away along with that prick. The last place I lived at, people did the same thing.
I never would do a thing like that. If I am uncertain about something, I ask first. I don't just go digging into someone else's food. I don't give things away tat don't belong to me. Unless they are left behind and forgotten about. Use a little common sense.