Hi, it could be a number of thing really.
They could be pining for mum if you'v recently took her away, especially if you didnt wean them gradually.
Its like having a new born baby. Just go through a list of things that could be upsetting them.
Check your feeding the right amount and at the right times as they might still be hungry.
I usually feed mine a puppy milk after each feed to compensate for the lack of mothers milk.
Check theyve been wormed correctly.
Make sure theyre warm, plenty of clean bedding / blankets etc..
You could also try a hot water bottle wrapped in a blanket. I find my pups love this in the winter.
Also try adding a few toys to keep them ocupied, they might be bored!
I hope this has helped a bit if you hadnt already thought of these things.
Let us know how you get on.
Best wishes.

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