Some back ground info about my 2 kids involved: difficult child 1 can get violent. When easy child 1 was 2 months old he kicked her in the head. He was about 8 years old at the time. She has no fear of him. A while ago (as in months) I come around the corner to see difficult child 1 repeatedly swinging his fist as close to her head as possible without getting her. She wasn't even flinching. She is very tiny for her age. She fits the 2T size of clothes. She turns 4 in Nov. easy child 2 is getting bigger than easy child 1. Now the problem. She has taken to teasing difficult child 1. He hates sneezing and coughing so she will sneeze and cough on purpose. I try to punish her. I try to teach her. I try to separate them. I try to teach difficult child 1 not to react to the teasing. This has been going on for months. difficult child 1 is starting to blame every problem he has on her (even if she doesn't have anything to do with it) and express the desire to physically hurt her.