Did Barbara and Adam seem to get confused about when they're supposed to hide?

This always has and will be one of my family's favorite films, but something still bothers me: it seems like Barbara and Adam keep forgetting that they can't be seen by living people. Sometimes when I watch it, I'm kind of confused by the hiding/lack of hiding in plain sight that Barbara and Adam do throughout the movie after they've been killed. It's like, being ghosts they get too confused about when they can be seen. For instance, when Adam's head is off and Barbara hangs in the closet ripping off her own face, Otho, Delia, and Charles can't see or hear them, thus they have no reaction to these things happening. Charles doesn't even react when Barbara runs over to him and gets in his face yelling, "What's the good of being a ghost when you can't frighten anyone away?!" Then, while they still can't be seen, after Lydia takes pictures of them, there's a scene where Delia is cooking in the kitchen talking to Lydia about the pictures and meanwhile, Barbara and Adam are hiding trying very hard not to be seen when it was already explained that Delia can't see them but Lydia can, and Barbara and Adam even whisper like they don't want to interrupt Delia and Lydia's conversation. Then when Delia, Lydia, Charles, Maxi, Sarah and Otho, are raiding the attic, meanwhile, Barbara and Adam are hanging outside of the window with sandworms hissing at their heels like they've already forgotten only Lydia can see and hear them and she likes them too much to let anything happen, but then it's explained that the others can't see them till after Otho's seance happens. Either that, or Barbara and Adam just aren't too familiar with the concept of hiding in plain sight, or they both failed hide and seek in when they were little, in kindergarten.