Light their blankets on fire.
Blast metal music on highest volume.
Tell them their father is being arrested by the cops outside.
Pour a bucket of ice into their bed.
Release a swarm of bees into their room.
Inject them with a shot of adrenaline.
Fire off a handgun near them (with blanks, obviously).
Fire off a handgun near them.
Get a fire hose and hose them out of bed.
Spray them with mace.
I think that’s enough for now…