Cats are, by nature, nocturnal, and kittens are naturally more active than older felines. In order to improve your slumber, you will need to change their sleeping and eating pattern. Toys should be kept at the end of the day; if they are left lying around your cats will continue to play once they get bored, especially at night when their nocturnal instincts kick in.
You will need to allocate some time for play before bed and give them their final meal before the day ends – i.e. not at 6pm but preferably before your own bed time. The objective is to tire them out and then fill their stomachs.
Playtime will be useful to stimulate their predatory instincts. Tease them with wand toys or encourage them to chase objects as this will definitely exhaust them. It is also important to allow them to cool down after rigorous activity. Feed them right after that. Cats are more likely to sleep after a heavy meal. Continue this routine every day for the next two weeks or so and they should mellow down.
Chamomile, a natural herb, also helps in calming pets. Try adding some in their food but be sure to start with a small pinch to make sure they are not adverse to it. Another way to get them to stop scratching your bed would be to stick double-sided tape on the areas where they often do so as cats hate the feeling of sticky tapes on their paws.