scared chickens staying in their nesting box

This is not something they will grow out of. They are hiding in the nest because the bullies are terrifying them. If they don't hide in the nest to get away from the bullies, the bullies may very well peck them to death.

 

Silkies are very often at the bottom of a mixed breed flock pecking order. They most likely will not grow out of it and your bullies will not just stop. You probably either need to separate them from the bullies, start over on integrating them (and it may not get any better no matter how long you take if you have serious bullies in your flock), or, as you suggested, rehome them. Other questions, are the ones who are doing the bullying hens, you are sure they are not roosters, and you are sure the two silkies are not broody?

 

I am not going to Mince words, and I hope you do not think I am rude; but . . .

It IS SERIOUS ALREADY. If something is not done about the bullying from the older hens, either they will suffer from not eating and drinking OR the older hens CAN AND WILL peck them to death.

These hens are just doing what chickens do.....

You need to separate them ASAP. There are many different threads here to help you with this problem. Good luck, I know how distressing this can be.

 

So glad to hear it!

Just wondering, when you did this integration, did you follow the slow integration process often recommended here? If you did, then you can stop reading! If you didn't, you may want to read about this and follow the process for the next time. The slow integration method basically consists of housing the new and exiting flocks side by side with a fence between them for AT LEAST a week. There is more to it than this but that's the general idea and you can read up on all the details it if you want. Just search on "how to integrate new chickens" or something like that.

I suggest this because this method will often avoid the stress and risk that your silkies experienced. It's certainly no fun for the new chickens to get picked on and to fear for their lives for several weeks while they work it out. Stressed chickens are also far more susceptible to illness too. It also can create the situation where normal chickens learn to be aggressive and then you have an ongoing aggression issue with one of them that you would have otherwise avoided. All sorts of reasons to take the cautious route that pays off in the short and long run!

Anyway, hope this helps,
Guppy