Hi Flame and
to Purrs
What were the cats like when you allowed them into the bedroom the 3 mths before? Did they settle when they were allowed in and were happy? If so it may well be that they are jealous of your little lad and trying g to get back into the room again.
There is a good article on Cats that are showing signs of being jealousy with a new baby on Messeybeast here
http://www.messybeast.com/cat_baby.htmbut i think the site is down at the mo.
From what i have read from cat behaviour books, the thing to do is try very very hard to ignore them, even a look or a shout will signal to them that the scratching gets a reaction from you and will learn to continue doing it. You have to be totally quiet and show nothing. Also their needs to be a comfy place for them to want to settle down in with all their needs elsewhere, have you tried a radiator beds in another room, somewhere temping they want to go. That and ignoring them works after a while and they learn that the attention seeking just doesn't work anymore.
In the books i have read on this by cat behaviourists, they say the attention seeking can get worse before it gets better, one cat who used to scratch at door and keep the humans up all night, went to jumping on the kitchen units and knocked a item over to make a loud noise. That def had the effect he wanted by the humans running downstairs to him. Crafty cat!! These people did solve the sleepiness nights by making sure their was nothing the cat could push over in the kitchen and persevered over a number of night ignoring the door scratching. They did provide in an alternative a snuggly hide away new bed in another room where the cat loved to sleep.
I hope this may help
Let us know how you get on