I am in similar situation. Routine can help in some cases. When you have a routine your wife and kids know when you will leave the room and when you will go back in (or the cave as my wife calls it :D). Sometimes it can be hard to take breaks at the same time everyday, especially when you are trying to figure out a problem you believe you are very close to solving. However, sometimes that break is all you need to fix that pesky bug! Headphones are also helpful, though like you I am a night owl as well. The only problem with that is that it can lead to irregular sleep, a subject a would like to read more about from a programmer who works at home with a family.