Be Good Ertie/ET

I read Be Good Ertie/ET. I reckon the brother could have kept ET more hidden. I found out that aliens like ET have very long fingers and have a very long neck. I didn't know that aliens had a large head like a pumpkin. Here is a picture of ET that I found on Google images.

I didn't understand why the big brother brought ET into the house and kept him in there. If I found an alien I don't think I would bring it into the house.