Fussing Frequently All Night long?!

My girls are 6 weeks on Saturday. They were born at 33w3d so they have not yet reached their actual due date (sept. 6). They are wonderful babies and sleep soundly during the day when they aren't eating. At night, they go down to sleep fairly well but only sleep 20-40 minutes before they start fussing and making all kinds of noises. Half the time they are not awake but if left alone the noises wake one another up and they turn to cries. So I am constantly up putting soothers back into mouths or rocking one of them. It's also hard to determine when these fussy times can be solved by feeding them and when they simply need to be comforted and laid back down.

Anyone have any tips? Is this constant noise making a twin/preemie thing? Theybare quiet and solid sleepers during the day, but I typically hold/cuddle with them for their naps 🙈.