My weird ass habits are universal to everyone that lives in my house. We get them all from mom, I don't know how dad puts up with us.
-Give voices / personalities to all the animals in the house to make them talk to me when no one is home, or talk to other people in my house, with everyone in my house doing the exact same thing and giving the animals voices to talk back.
Each animal as a specific voice, tone, attitudes and sometimes accents that everyone in the house will mimic and stick to, it does not change between people.
-Someone in my house will just randomly break into song, it will not be a known song it'll be one they are making up on the spot right then. I or someone else will join in, making up lyrics as we sing along, then another. Sometimes someone will join in twice more more by adding the animal voices. It continues until someone gets stuck in thinking up and verse and ruins the song.
-Just... randomly making noises as you go through the house. If someone else is doing it we end up facing off as we randomly make noises at each other that progressively gets louder and more screechy until one of us either stops and continues on their way or can't go any higher.