Due to their street-cat backgrounds, they are much more active in the night than your usual UK moggy. The night time is the time that street cats can roam around without people trying to get at them.
This does mean that things in your home are likely to go bump in the night, you may come down to find things upside down in your home because your cat has gotten excited and had a zoomie session (high excitement, running around, jumping around and scaling things).
Zoomie sessions can happen at any time - you may see you cat zoom past you and do some strange things in the process. This is normal, a way to counteract it is to ensure they are getting enough play and mental stimulation.
Zoomies can also mean claws... It can happen when a cat becomes excited, stick their claws in and climb you like a tree, or hide behind a door and jump out and claw you as you or your child are walking by, they may even charge you and claw you if excited or aroused. It is important to remember that they are not attacking you or your child, they are excited and this is how cats play.