LO constantly makes noises at night but..

She seems to sleep very calmly at naps. She just lays there, doesn't toss and turn, doesn't make noises. But at night. Wow. She's constantly kicking her legs up and down, her arms are flailing about. She manages to change her position in bed in a 90° turn. She grunts or makes whimpering noises, sometimes lets out a single cry. Then she may go silent and still for a couple minutes but then starts up again. Swaddling doesn't help. Why can't she sleep peacefully and calmly at night like she does for naps? I thinking she's not getting a good nights rest when she makes all those noises and movements. I know me and her dad aren't! She's 8 weeks.