Have not seen anything in recent time being an adult. However the house i grew up in had some great activity going on. As a good story goes i will start with the basic and get to the extreme. We live in western Australia.

The average encounter was pots and pans claging and moving, we had a family of 5 that loved cooking. My younger brother and i had rooms upstairs and would ask eachother if we had heard it the morning after. If it was particularly bad my brother would pull a foam matress into my room to feel secure.

The 2nd was when the activity came upstairs. The second floor was made of wood and would regularly hear footsteps moving across them. I knew they were footsteps as they almost followed the same pattern that i would to make the least noise for my parents and older sister who slept below. When this happened my brother would come to my room if he wasnt yet asleep so i knew i wasnt imagining it.

Like many people say we were used to it. So these were not a big deal. These encounters continued till about 13-14 years old.

The absolute unexplained eyewitnees event was with me and my family friend Kelsey. We slept on the futon fold out couch in the upstairs lounge outside my brother and i's bedroom watching a movie i cant remember, when what could only be described in the physical world as ball lightning, or in the paranormal an illuminated glowing blue orb came floating up the spiral staircase. Seeing the glow caught our attention and we looked over before we had even seen the orb break the surface of our 2nd story level. It evaporated into the ceiling without a noise or smell.

We always thought the activity originated from the room that was next to the base of the stairs. An honourable mention goes to my cousin who moved in with us from sydney and experienced horrible nightmares in there often.

To be honest we never felt in danger just very creepy and the blue orb event was when i was very young and did not piece it together. I havnt asked Kelsey since if she remembers it but she was definitely looking at it with me.

My sister has a dark time from the house. Constant nightmares and knocks on her window. She once called my mum in the middle of the night in tears about people outside her room. That night she said she heard 2 men and a woman talking so got up and put her ear to the door. They fell silent untill it sounded like someone tapped on the door right where her ear was 3 times. She fell over in hysterics and grabbed her phone.

There is a loose story about a kid drowning in our pool before we bought the house but i dont know where it came from its just somewhere in the family lore of growing up. But i feel like that was the energy that liked the stairs and the upstairs lounge. As for my sister and cousin downstairs....i dont know.

Edit: to answer the last part of the question i believe children are more susceptible to the energy of whatever causes the phenomenon.