It's kind of unusual for a child of seven to develop a sudden irrational fear. Have you talked to both kids teachers to find out if they have displayed a change in behavior at school as well? Even if the teachers say school is okay, go and have lunch with both younger boys at school a few times and watch their behavior. If all is well at school, take mental stock of any events that may have occured at home. Have you moved recently, installed a new major appliance that makes spooky noises, changed their sleeping arrangements, introduced a new person or pet to the home, etc.? Also, there is a decent age gap between your oldest son and the two younger ones. Do they have a good relationship? If you find the younger children are avoiding the oldest, there might be some teasing going on. I used to annoy the heck out of my older brother and even though he was an otherwise great kid, he wasn't always very nice to me. We both laugh about it now, but we were actually pretty cruel to each other at times, and my mother never even knew until we were both adults. If none of those possibilities apply, it is time to investigate. My seven year old daughter and several of her classmates have recently discovered Goosebumps books, which are available from the school library. Although they are age appropriate books, they are also very spooky, and include stories about ghosts, werewolves, and other monsters. My daughter would never admit that these stories creep her out, but just last night she asked to sleep in my bed with me. I found that odd since she read six of the Harry Potter books and wasn't creeped out once, even when major characters died. I think the difference was that none of the other kids were reading Harry Potter, whereas a lot of them are reading Goosebumps and talking about how scary the stories are. But kids are funny like that, you never know what's going to give them the heebie-jeebies. Ask your seven year old if he has been reading material like that or if he has happened across a T.V. program that may have frightened him. Some of the trailers they show on T.V. for horror movies give ME the creeps! Also, look within your own home for material that is less than warm and fuzzy. My mother was always an avid reader and especially loved horror stories. The covers on some of those books were terrifying to me as a child (a monster coming out of the toilet, a dark shadowy figure watching children play, zombies, bones, blood and knives, etc.) Kids are curious, and your middle son is at that stage where he really starts investigating his environment (ie: the whole house and possibly other people's personal belongings). And last, if the relationship between the oldest boy and the younger ones is good natured, maybe he can help with the problem. It's not unusual for a child to be more willing to open up to a sibling than a parent. Good luck!