What kind of things do you hide from your siblings?

I hide everything from my siblings. They are really annoying nowadays and I do not know why, but they borrow everything from me. My sister, will see something she likes and just take it; she will not ask or tell me she took it even, but then when I go to find that thing that she took it will not be there and I have to spend the rest of my day looking for it because, most likely she used it and then just put it somewhere and she does not even know where it is. My brother will use my earphones all the time. We both have the same iPod and left his iPod ear phones, that are great by the way, at a relatives house and as a result, takes mine, even when I need it. I hate this. See, he will ask me if he can use them when he is going to the gym and I will resist at first and then say yes later and he will take them and forget to take them back. In the morning, I will be off to school and will want to listen to my iPod on the way there because its a long walk and there will be no iPod earphones in sight. He usually leaves before I do to school which means I am left without no earphones and he did not even think to give mine back to me. I feel bad because he has no earphone and I know what a hassle it can be at the gym without music so I give it to him but why would you not give them back when you come back from the gym? this is what makes me most mad about my siblings and they are really annoying. My parents always ask me why I lock my door when I go somewhere but can you blame me?

I actually don't remember hiding anything from my brother. With just the 2 of us we had very strict rules about things that we would both abide by.

For instance, we would always share everything equally. If our mother bought a box of 3 Magnums 1 each from there we would be for each of us. When we decided to eat it was our business, the other would not be touched. Same with even a can of coke. If there was 1 left we would puor it into 2 glasses equally.

We even had a rule for the remote. First one in the room controls the remote. If you leave the room you lose control.