Hi Adrienne, thanks a lot for replying. First of all, the problem is much more pronounced at night. While it also manifests during daytime, it is much milder and manageable then. We don't have any problems when he is fully alert and actively interacting with all of us. The problem usually occurs after he "settles down" for some time beside a family member (ex. he lies down at my daughter's feet or under the chair that my wife is sitting on, etc.). Once he settles down for some time in that position, he sometimes reacts if any one of us (even another family member) approaches him and the family member he is with at that time. Its like he turns into a guard dog for that person (even against other family members). So we always try to make sure we telegraph and/or announce our approach and that usually minimizes any negative reaction from him (interestingly, he also sometimes reacts if the family member he is with makes sudden movements and so whoever is with him when he is in that state also tries to make his/her movements gentle/slow). When he does react aggressively, it seem as if he momentarily forgets that he knows the other family member that approached. So what we do is to talk gently to him/move slowly after which he usually calms down. However, as I mentioned at the start, the problem is more severe at night. There was a time when my daughter slept in our room in a sleeping bag for a few days and he slept beside her. He would get up and growl even at me when I passed close at to them. Maybe its a combination of protective behavior and disorientation when he is drowsy. I tried an Adaptil collar on him but it didn't really make any difference. Not sure what else to do to change his behavior. He is really a sweet dog although he does seem to have an anxious personality and maybe that is also a factor. He generally does not like loud noises and gets easily triggered by them. He does bark at strangers, the mailman, other passing dogs, etc. but only when he is at home and he sees them outside (he is meek when walking outside with a leash). Thanks a lot for trying to help!